This 'n' that

Bill Spight · **#341**

AlphaGo vs. AlphaGo Game 46

Sanrensei

Click Here To Show Diagram Code: [go]$$Wcm6 Sanrensei $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 3 . . . . . . . . . . . . . . . | $$ | . . 4 O . . . . . a . . . . . X . . . | $$ | . . 6 7 . . . . . . . . . . . . . . . | $$ | . 8 5 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . 1 . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black played sanrensei, which surprised me a little, since it has gotten a bad rap in recent years. At first glance, it doesn't seem bad in theory, but its stats have not been so great. One problem is how to respond to the approach, :w6:

? Local replies have not fared too well. Maybe yonrensei at "a" is good. AlphaGo offers an answer, the AlphaGo 3-3 invasion in the top left corner.

Which side to block on? I think that we can consider some of these invasions as probes. White chooses to block on the side facing the sanrensei instead of the side facing the White corner stone. :w10:

is perhaps the usual choice, instead of playing hane at the head of two stones. It is not an AlphaGo innovation, but the subsequent play is. Humans have been playing the keima to take sente. White does take sente, but after a new sequence. :b7:

-

is a new, AlphaGo joseki.

White gets a wall, but one without either eye shape or an extension. No matter, says AlphaGo. :cool:

Click Here To Show Diagram Code: [go]$$Wcm14 3-3 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . 8 9 . a . . . | $$ | . . . . . . . . . . . . 7 6 0 . . . . | $$ | . . . O . . . . . , . . . 5 4 X 2 . . | $$ | . . . . . . . . . . . . . O . 3 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

jumps into the corner. I don't think that we can conclude that AlphaGo's choices are the only good plays, or even the best. The double approach at "a" has good stats, and I doubt if humans will give up on it or other plays. The play through :b23:

is joseki.

Click Here To Show Diagram Code: [go]$$Wcm24 The fight begins $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . 7 . . 6 . . . . . | $$ | . . . . . . . . . . 3 2 X W . . . . . | $$ | . . . . . . . . . 8 4 1 O X X . . . . | $$ | . . . O . . . . . , . . . O X X X . . | $$ | . . . . . . . . . . . . . O . O O . . | $$ | . . . . . . . . . . . . 5 . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White might consider playing :w26:

at 27. How bad can it be to crawl along the 5th line?

Besides,

is a good play, necessitating :w28:

. But

takes advantage of the aji of :wc:

.

and

are good.

Click Here To Show Diagram Code: [go]$$Wcm32 Kikashi, Eye stealing tesuji $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . 5 . . O 3 1 X . . . . . | $$ | . . . . . . . . . . O X X W 2 . . . . | $$ | . . . . . . . . . B B O O X X . . . . | $$ | . . . O . . . . . , . . a O X X X . . | $$ | . . . . . . . . . . . 6 . O . O O . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

fills at

White takes his kikashi and then :w36:

bolsters White's central stones while attacking the :bc:

stones and building central influence.

:b37:

is the eye stealing tesuji, threatening to cut at "a", which captures two white stones and saves the two endangered :bc:

stones.

Click Here To Show Diagram Code: [go]$$Wcm38 Be my guest! $$ --------------------------------------- $$ | . . 8 . . . . . . . . . . . . . . . . | $$ | . 4 1 6 7 . . . . . . . . . . . . . . | $$ | . a X O . . . . . . . . . . . . . . . | $$ | . . X O . . . . . , . . . . . X . . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O 3 . . . . . . . . . . . . . . . | $$ | . 5 . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . O O O X . . . . . | $$ | . . . . . . . . . . O X X X X . . . . | $$ | . . . . . . . . . B B W W X X . . . . | $$ | . . . O . . . . . , . . 2 O X X X . . | $$ | . . . . . . . . . . . B . O . O O . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

is surprising. Who doesn't connect to a peep? Especially as connecting leaves the :bc:

stones weak and attackable. Maybe this was a mistake. (Black did win the game, after all.) OTOH, connecting gives White bad shape, and the :wc:

stones have done work, permitting the White kikashi with :w32:

and

. So maybe they are expendable.

AlphaGo as White chose to sacrifice the :wc:

stones and play kikashi against the top left corner, in the process building influence in the center and left side. :w40:

is very nice in that regard, as opposed to, say, the hane at "a", which looks tempting.

prepares for :w42:

, which is also big.

Click Here To Show Diagram Code: [go]$$Wcm46 AlphaGo joseki $$ --------------------------------------- $$ | . . X . . . . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . 9 7 . . . . . | $$ | . . X O . . . . . . . 0 8 4 5 3 1 . . | $$ | . . X O . . . . . , . . . . 6 X 2 . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O O . . . . . . . . . . . . . . . | $$ | . O . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . O O O X . . . . . | $$ | . . . . . . . . . . O X X X X . . . . | $$ | . . . . . . . . . X X O O X X . . . . | $$ | . . . O . . . . . , . . X O X X X . . | $$ | . . . . . . . . . . . X . O . O O . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Next, White plays another AlphaGo special in the top right corner.

This time

is played with the idea of building thickness, not of taking sente. (Anthropomorphizing a bit. AlphaGo does not make plans, OC.

)

Click Here To Show Diagram Code: [go]$$Wcm56 Central moyo $$ --------------------------------------- $$ | . . X . . . . . . . . . . . . . . . . | $$ | . X . X O . . . . . . . O O . . . . . | $$ | . . X O . . . . . . . X X X O O O . . | $$ | . . X O . . . . . , . . . . X X X . . | $$ | . . X O . . . . . . . . . . . . . . . | $$ | . X O O . . . . . . . . 9 . . . . . . | $$ | . O . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . 1 . . . . . . . | $$ | . . . , . . . . . , . . . . . X . . . | $$ | . . 3 . 7 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 . 6 . . O . . O O O X . . . . . | $$ | . . . . . . . . . . O X X X X . . . . | $$ | . . . . . . . . . X X O O X X . . . . | $$ | . 4 . O . . . . . , . . X O X X X . . | $$ | . 8 5 . . . . . . . . X . O . O O . . | $$ | . . . . . . . . . . . . O . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

builds the White central moyo while preventing Black from extending her moyo on the right. A Black play at or around 56 would be good, eh?

enters the left side. White pincers it and builds up his huge moyo while (hopefully) holding the fort in the bottom left corner. :w64:

reduces Black's moyo while extending White's. White's center oriented play in this game is reminiscent of Go Seigen's.

Bill Spight · **#342**

AlphaGo vs. AlphaGo Game 48

Click Here To Show Diagram Code: [go]$$Bc Game 48 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 4 . 0 . . . . . . . . . . . . . | $$ | . . 8 , . . . . . , . . . . . , 1 . . | $$ | . . 6 5 . . . . . . . . . . . . . . . | $$ | . . 7 9 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . a d . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . b . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . , . . . . . , . . . | $$ | . . . . . c . . . . . . . . . 3 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Nothing unusual so far.

When I was learning go it was already known that there is a problem with this joseki ending with a Black play at "a" to make a base — at least, early in the opening. One way to avoid the problem is to omit :b9:

and play elsewhere, for instance, enclosing the top right corner. Another way is to follow with Bb - Wc, Bd, staking out the left side and extending on the fourth line instead of the third.

Click Here To Show Diagram Code: [go]$$Bcm11 What, me worry? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . 3 . , X . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . a . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . . . 2 . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

AlphaGo shows another way. Play the exchange, :b11:

-

, and then play elsewhere. :shock:

In this case Black plays the two space high enclosure in the top right corner. AlphaGo likes this enclosure, and it will probably become more popular as a result.

Black allows White the good play at "a", but is unconcerned.

Click Here To Show Diagram Code: [go]$$Wcm14 No rush $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . X . , X . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 3 . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 1 . . | $$ | . . . O . . . . . , . . . 2 . , . . . | $$ | . . . . . O . . . . . . a . . B . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White does not hurry to make the good play at :w16:

, but approaches the bottom right corner, instead. Black could go back and play at 16, OC, but then White might pincer the :bc:

stone. If Black pincers :w14:

, White might play a counter pincer. :b15:

at "a" would allow White to press down at 15. I like :b15:

.

(Not that I would have left the left side wide open.

)

Click Here To Show Diagram Code: [go]$$Wcm14 Still not worried $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . X . , X . . | $$ | . . O B . . . . . . . . . . . . . . . | $$ | . . B B . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 3 . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . 4 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 1 . . | $$ | . . . O . . . . . , . . . 2 . , . . . | $$ | . . . . . O . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Even after the double pincer at :w16:

, Black does not respond, but makes a pincer on the right side. Now, the single Black stone is not of much concern, as it is just one stone. But what about the — ahem — Black wall, such as it is, in the top left. Those three :bc:

stones have no eye shape and no base. How does Black keep those stones from becoming heavy baggage, if they aren't already?

Now, in my comments I have characterized some of AlphaGo's plays or stones as thin or heavy. I really should not do that, because those are go terms indicating incorrect play, and I cannot apply them to AlphaGo's play. Not that AlphaGo's play is perfect, OC, but I cannot show those errors. A better term for AlphaGo's play in these cases is light. Light and thin are cousins, so it is easy to see how a play that looks thin could actually be light. But light and heavy are opposites. How to keep eyeless stones from becoming heavy? It is important, I think, to treat them lightly, to be flexible and to be prepared to sacrifice them.

I think that omitting D-10 in this position is an AlphaGo innovation, one which I think pros will copy. But omitting the extension from the :bc:

stones is not new, going back at least a couple of centuries, although the extension is by far the usual play.

Click Here To Show Diagram Code: [go]$$Wcm18 Double attack $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . X . , X . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . 8 . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . 7 . . . , . . . . . , . . . | $$ | . . . 5 . . . . . . . . . . . . X . . | $$ | . . 3 4 6 . 9 . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X 2 . a 0 . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . O . . | $$ | . . . O . . . . . , . . . X . , . . . | $$ | . . . . . O . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The kick at :w18:

launches a double attack. I like to play White in these situations, but AlphaGo as Black invited the attack. :b25:

jumps out from the upper group, perhaps because the lower one has more flexibility. :w26:

is strong, topping the tree. Note :b27:

. Black could have made a table shape with "a", but :b27:

is lighter. Black looks ready to sacrifice two of the stones in the lower left.

Click Here To Show Diagram Code: [go]$$Wcm28 Sideways attacks $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . 3 . . , . . . X . , X . . | $$ | . . O X . . 4 . . . . . . . . . . . . | $$ | . . X X . . X . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . 6 . , . . . . . , . . . | $$ | . . . O . . . . . . . . . . . . X . . | $$ | . . O X X . O . 5 . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X . . X . 2 . . . . . . . . . . | $$ | . . O . . . . . . . . . . . . . O . . | $$ | . . . O . . 1 . . , . . . X . , . . . | $$ | . . . . . O . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Often in an attack you want to get ahead of your opponent. Pushing the cart from behind usually makes it easy for him to escape. One thing I noticed in Okigo Jizai is how often Hattori plays an attack from the side. Both :w28:

and

are sideways attacks. Because of the solid White corner, the one in the top left looks slow, but AlphaGo likes it. Both of them prevent shoulder blows, which would be big. :w32:

is another sideways play, but :b33:

launches a counter-attack.

White eventually won the game, but Black's light treatment of the three Black stones in the upper left is characteristic of AlphaGo's play. Such flexibility is not unique in the history of go, but, looking at AlphaGo's play against today's pros, I think that its skill in that aspect of the game is supreme. Much food for thought there.

Bill Spight · **#343**

AlphaGo vs. AlphaGo Game 4

Click Here To Show Diagram Code: [go]$$Bc Opposing 3-4s $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 1 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 4 . . . | $$ | . . . 3 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

By symmetry we know that the net count of this position is 0. But the opposing 3-4s on the left side are supposed to favor the first player. As we would say now, the global temperature is greater than that of the empty board, so Black can overcome komi. The argument, which I learned as a beginner, goes like this.

Click Here To Show Diagram Code: [go]$$Bc Good move for Black $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 1 . . . | $$ | . . 5 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 7 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 6 . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . 4 . . . | $$ | . . . 3 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After

,

preserves symmetry, but then Black gets the good play, :b7:

, a combined extension and pincer. OC, White does not have to approach the bottom left corner with :w6:

, but then Black can enclose it.

Well, that's the theory, anyway.

But pros have still played opposing 3-4s from time to time. And White won this game. Not that :b7:

isn't a good move, but the theory remains unproven. Something else we won't be teaching beginners anymore.

Click Here To Show Diagram Code: [go]$$Bcm5 Will he or won't he? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . 6 . . . . . . . . . . . . . | $$ | . . 4 , . . . . . , . . . . . X . . . | $$ | . . 2 1 . . . . . . . . . . . . . . . | $$ | . . 3 5 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . a b . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black played the high approach, and White made the popular response. Joseki so far. But will Black play the extension to "a", or maybe "b"? Or maybe Black will make no extension at all, and enclose the bottom left corner.

Click Here To Show Diagram Code: [go]Bcm11 Mini-Chinese? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Of course not. :b11:

makes a kind of Mini-Chinese shape. This is, I think, another AlphaGo innovation, but it would not have appeared strange to the players of two centuries ago. Not only did they play the Mini-Chinese in handicap games, they often played extensions in the opening that are wider than the extensions to make a base. I expect that AlphaGo is reviving that style of play.

As I have mentioned before ( viewtopic.php?p=211817#p211817 and following posts) the idea of making a base in the opening is quite ancient. Long ago, players even preferred to play a wedge, leaving enough room to make a base on either side, in situations where modern players would most likely pincer. Also, extensions often leave room for a two space extension, to be able to make a base if the opponent invades. And six space extensions are considered questionable, as they leave room for an invader to make a two space extension. Takagawa, known for his skill in the opening, said that the main reason for playing in the corner was not because it is easier to make territory than elsewhere, although that is so, but because it is easier to make a base. Much of traditional opening theory derives from the importance of making a base. But, early in the game, AlphaGo does not seem to place much emphasis on making a base. It often makes longer extensions. This is not exactly new, as the play of a couple of centuries attests, but AlphaGo's play threatens the very foundations of traditional opening theory. Fan Hui said that AlphaGo stresses efficiency over making territory, but of even more theoretical significance, I think, is that it stresses efficiency over making a base.

Click Here To Show Diagram Code: [go]$$Wcm12 Go Seigen shoulder blow $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . a . . 2 3 . O . . . | $$ | . . . X . . . . . . . . . 1 . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

is the modern, quasi-enclosure in the bottom right corner. (White makes a base instead of extending to "a", what can I say?

) Some people would call :b13:

an AlphaGo shoulder blow, but Go Seigen advised this play, when Black has a stone in the bottom left corner, in his 21st Century Go books.

responds in the corner. Where does AlphaGo play next?

Click Here To Show Diagram Code: [go]$$Bcm15 Close approach $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . a . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . X O . O b . . | $$ | . . . X . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Who would have guessed this play? Oh, the main point is easy to grasp. :b15:

spoils White's development on the right side. A White play at "a" would be over concentrated. But by the same token, a Black play at "a", while it makes a base, is smaller than the typical two space extension. Black would be cramped. And in the actual game Black did not play at "a" but make the attachment at "b", and did not make a base in the bottom right.

Click Here To Show Diagram Code: [go]$$Wcm16 Another Go Seigen play $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . a . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . 2 . . . . . . | $$ | . . . , . . . . . , . . X O . O . . . | $$ | . . . X . 3 . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

approaches the top right corner and prevents Black's development here. Note that :w16:

has room to make a base at "a". :b17:

extends to the 5th line, a big play. :w18:

approaches the Mini-Chinese from the bottom side, another Go Seigen idea (although this approach to the 3-4 also goes back to antiquity).

Click Here To Show Diagram Code: [go]$$Bcm19 High pincer $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . 3 . . 2 . . . . . X . . . . . . | $$ | . . . , . . . 1 . , . . X O . O . . . | $$ | . . . X . O . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

is a high pincer. After :w20:

secures the corner. Where does White play now?

Click Here To Show Diagram Code: [go]$$Wcm22 Zwischenzug $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . X . . | $$ | . . . . 1 . . . . . . . . . . . . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ | . . . X . . O 3 . . . . X . . . . . . | $$ | . . . , . . . X . , . . X O . O . . . | $$ | . . . X . O . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Plainly, White wants to press with :w24:

. But first White plays kikashi, a reducing play at :w22:

. Note that after Black protects with :b23:

, White still threatens the left side.

Click Here To Show Diagram Code: [go]$$Wcm24 Choshi $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . X . . | $$ | . . . . W . . . 7 . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . X . . O 1 3 6 . . X . . . . . . | $$ | . . . , . . . X 2 4 . . X O . O . . . | $$ | . . . X . O . . . . . . . O . . . . . | $$ | . . . . . . . . . . . 5 . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

-

are choshi, a term that has been variously translated. The general idea is to force the opponent to force you to make a play that you want to make. The keima, :w28:

, is a good play in itself, but after :b25:

-

, it is even better. Note how the :wc:

stone (

) helps to give White some eye potential in the center. Both sides have played a nice opening.

Now let's fast forward to the early middle game.

Click Here To Show Diagram Code: [go]$$Bcm63 Base? What base? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . 3 . X . . . | $$ | . . O X . . . . . . . . . . . . 1 . . | $$ | . . X X . . . . . . . . 6 . . 2 W . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . O . . . . . . . . . . . . . | $$ | . . X . . O X X . . . . . . . 5 b . . | $$ | . . . , . O O X . , . . . . . , a . . | $$ | . . . . . . . O X . . . . . . . . . . | $$ | . . X . . . . O X . . . . . . . X . . | $$ | . . . . O . . X O X O . . . X f e 4 . | $$ | . . . X . . . . O O . . . O X O c d . | $$ | . . . X . . O O O X . . X O X X O O . | $$ | . . . , . X X X X X . . X O . O X X . | $$ | . . . X . O . . . . . . . O . O O . . | $$ | . . . . . . . . . . . O . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The kick,

, initiates an attack against the :wc:

orphan. White could make a base with "a" or "b" instead of :w66:

. White prefers to allow the pincer, :b67:

, and then run out with :w68:

. Why White made that judgement, I cannot say. But note that :w66:

takes away Black's potential base here. Black could make a base with Bc - Wd, :b66:

- We, Bf, and White cannot connect.

AlphaGo's play in this game and others demonstrates that AlphaGo is less concerned with making a base than with efficiency. IMO that will have a profound effect upon go theory.

John Fairbairn · **#344**

Bill

Interesting thoughts! First, just parenthetically, omitting D10 has been tried by humans before (Takagawa, Kobayashi, etc), but is admittedly rare.

Your most intriguing comments are about using "light" in a new sense. I likewise have come to the conclusion that we need to re-invent the vocabulary somewhat to start making sense of AlphaGo's plays.

The best approach we have both adopted seems to be to say it's just like Go Seigen (and it's fascinating and exciting that Yoda's forthcoming book on AG will focus on its similarities with Go and Dosaku). I think that means a lot to us and anyone else who has been through the corpus of Go's games, but it's very hard to be specific or to generalise.

Rather than the light/not-heavy focus you have been taking, I have been thinking on other lines which may well end up at the same place. My thoughts have focused on thickness, which I think has been the dominant theoretical theme in pro talk for close to a century now. I'm sensing that AG seems to eschew that and to focus rather on influence (from which thickness may develop, but that's by the by as far as AG is concerned).

However, AG seems to focus on influence in a quite different way from us. I think we see influence as tied in with thickness - they are on a continuum - and so I have an impression that most of us feel that subsequent play is somehow towards that influence/thickness (driving the enemy towards it), or staying out of its shadow (keeping away from it). Either way, it is the actual entity of influence/thickness that dominates the thought process.

AG, however, seems to see things more nebulously, in terms of an influence map. Rather than a wall and its shadow it sees a lake. Its focus is outwards. It seems to be able to see what effect outside stones will have elsewhere over a much wider area than humans do. What AG seems to be doing is what humans tried to analyse at the time of Shin Fuseki (e.g. the way they talked about the 5-5 point or tengen). The humans gave up because it was just computationally too hard, but at least they knew where to look!

My sense is that what I am saying does resolve into your thoughts on lightness. I know you've done some work on influence maps as well. Maybe we should revisit this? I feel sure even at this stage that we do need some new terminology, maybe based on influence maps. I'm attracted by the idea of basing it on water. Not just lakes, but fluidity, the notion of water being light and heavy, evaporating, freezing, mixing, diluting, etc. etc. Instead of food for thought, liquid for thought

(Mine's a double, neat, thank you.)

Uberdude · **#345**

Bill Spight wrote:

AlphaGo vs. AlphaGo Game 4

Click Here To Show Diagram Code: [go]$$Bcm11 Mini-Chinese? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Of course not. :b11:

makes a kind of Mini-Chinese shape. This is, I think, another AlphaGo innovation, but it would not have appeared strange to the players of two centuries ago. Not only did they play the Mini-Chinese in handicap games, they often played extensions in the opening that are wider than the extensions to make a base. I expect that AlphaGo is reviving that style of play.

There are 5 hits of the left side shape in waltheri, the oldest being Rin Kanketsu in 2010 and 4 in 2015 (other corners were usually black top right but not 4-4 and white bottom right). Making further extensions from the top left joseki when you have the corner beyond seems fairly standard to me, in fact I remember learning from some book (maybe A Dictionary Of Modern Fuseki, The Korean Style) that if you do the hanging connection and normal joseki extension it's inefficient with a 4-4 below (I recall playing as white against this on OGS and got a good result):

Click Here To Show Diagram Code: [go]$$Bcm11 Joseki inefficient (4-4 not helped enough) $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

So play a move which helps the corner too, and if white invades on the left around a you can jump out around b.

Click Here To Show Diagram Code: [go]$$Bcm11 Better balance $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . . . b . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . a . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

So anticipating this fight, in which black's hanging connection group is fairly flexible and can run out nicely, white may peep first, trying to make it heavier and less easy to jump out (on this half board on waltheri it has 68 games and 54.5% win, vs 89 games with 49.5% win for the one-space extension: not hugely significant but a valuable hint I think):

Click Here To Show Diagram Code: [go]$$Wcm10 White's counter $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . 1 . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Edit: P.S.

Quote:

if you do the hanging connection and normal joseki extension it's inefficient with a 4-4 below (I recall playing as white against this on OGS and got a good result)

Here's the game: how should black answer the approach the the 4-4? Maybe iron pillar? Because if you one point jump then 3-3 seems to be good for white as the smooth lead I got in the game seems to show.

Bill Spight · **#346**

Uberdude wrote:

Bill Spight wrote:

AlphaGo vs. AlphaGo Game 4

Click Here To Show Diagram Code: [go]$$Bcm11 Mini-Chinese? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . O . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Of course not. :b11:

makes a kind of Mini-Chinese shape. This is, I think, another AlphaGo innovation, but it would not have appeared strange to the players of two centuries ago. Not only did they play the Mini-Chinese in handicap games, they often played extensions in the opening that are wider than the extensions to make a base. I expect that AlphaGo is reviving that style of play.

There are 5 hits of the left side shape in waltheri, the oldest being Rin Kanketsu in 2010 and 4 in 2015 (other corners were usually black top right but not 4-4 and white bottom right).

Thanks.

I guess I flubbed the lit review. :oops:

Quote:

Making further extensions from the top left joseki when you have the corner beyond seems fairly standard to me, in fact I remember learning from some book (maybe A Dictionary Of Modern Fuseki, The Korean Style) that if you do the hanging connection and normal joseki extension it's inefficient with a 4-4 below (I recall playing as white against this on OGS and got a good result):

Click Here To Show Diagram Code: [go]$$Bcm11 Joseki inefficient (4-4 not helped enough) $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

So play a move which helps the corner too, and if white invades on the left around a you can jump out around b.

Click Here To Show Diagram Code: [go]$$Bcm11 Better balance $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . . . b . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . a . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Very interesting. Thanks.

Quote:

So anticipating this fight, in which black's hanging connection group is fairly flexible and can run out nicely, white may peep first, trying to make it heavier and less easy to jump out (on this half board on waltheri it has 68 games and 54.5% win, vs 89 games with 49.5% win for the one-space extension: not hugely significant but a valuable hint I think):

Click Here To Show Diagram Code: [go]$$Wcm10 White's counter $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . 1 . . . . . . . . . . . . . . | $$ | . . . X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wcm10 Black's reply? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X . 1 . . . . . . . . . . . . . . | $$ | . . . X 2 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . X . . . . . , . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Looking at the whole board, OC.

Bill Spight · **#347**

John Fairbairn wrote:

Bill

Interesting thoughts! First, just parenthetically, omitting D10 has been tried by humans before (Takagawa, Kobayashi, etc), but is admittedly rare.

Ah! Thanks.

Quote:

Your most intriguing comments are about using "light" in a new sense. I likewise have come to the conclusion that we need to re-invent the vocabulary somewhat to start making sense of AlphaGo's plays.

Yes, it does broaden the definition a bit. But I think that it is close to Rin Kaiho's understanding. In something I read long ago he said that keeping your options open (and generating options) is light play.

Quote:

The best approach we have both adopted seems to be to say it's just like Go Seigen (and it's fascinating and exciting that Yoda's forthcoming book on AG will focus on its similarities with Go and Dosaku). I think that means a lot to us and anyone else who has been through the corpus of Go's games, but it's very hard to be specific or to generalize.

I, like everybody else, I suppose, have found many of AlphaGo's plays surprising. But I don't find them alien or otherworldly. It's opening play, especially, reminds me of Go Seigen. I am also in general reminded of go of a few centuries ago, and of Kitani. I missed the specific Dosaku connection, though. I think that Yoda's book will be quite interesting.

Quote:

Rather than the light/not-heavy focus you have been taking, I have been thinking on other lines which may well end up at the same place. My thoughts have focused on thickness, which I think has been the dominant theoretical theme in pro talk for close to a century now. I'm sensing that AG seems to eschew that and to focus rather on influence (from which thickness may develop, but that's by the by as far as AG is concerned).

However, AG seems to focus on influence in a quite different way from us.

Yes. Looking at AlphaGo vs. human pro play, I have been impressed at how differently AlphaGo treats influence, and how much better. It seems like it utilizes it better and nullifies it better. As Brady Daniels says, "AlphaGo: Whatever you do is wrong."

( forum/viewtopic.php?f=10&t=13956 )

Quote:

AG, however, seems to see things more nebulously, in terms of an influence map. Rather than a wall and its shadow it sees a lake. Its focus is outwards. It seems to be able to see what effect outside stones will have elsewhere over a much wider area than humans do. What AG seems to be doing is what humans tried to analyse at the time of Shin Fuseki (e.g. the way they talked about the 5-5 point or tengen). The humans gave up because it was just computationally too hard, but at least they knew where to look!

My sense is that what I am saying does resolve into your thoughts on lightness. I know you've done some work on influence maps as well. Maybe we should revisit this? I feel sure even at this stage that we do need some new terminology, maybe based on influence maps. I'm attracted by the idea of basing it on water. Not just lakes, but fluidity, the notion of water being light and heavy, evaporating, freezing, mixing, diluting, etc. etc. Instead of food for thought, liquid for thought

(Mine's a double, neat, thank you.)

Well, there are problems with influence maps, which is one reason that, after four decades of research, go programmers never approached consensus on an evaluation function. AlphaGo's value network has to be an improvement on them, but, as moha indicates, it still needs to be supplemented by Monte Carlo rollouts.

I like your water metaphor.

As for humans, I think that the next generation will have a much better feel for the whole board than ever.

Humans are very good at picking up things that they are unable to articulate.

gowan · **#348**

In an earlier post in this thread Bill Spight commented on this move B15:

Click Here To Show Diagram Code: [go]$$Bcm15 Close approach $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . . . . . . . . . . . . . 1 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . a . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . X O . O b . . | $$ | . . . X . . . . . . . . . O . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

asking who would have guessed this move. I think Go Seigen might have guessed it. It plays first in one of Go Seigen's six regions, as do his far approach moves and shoulder hits.

jeromie · **#349**

I'm really enjoying your latest series of posts, Bill. Thanks!

(Thanks also to those engaging in conversation. I appreciate those contributions, too. :-)

)

John Fairbairn · **#350**

Bill

Quote:

Well, there are problems with influence maps, which is one reason that, after four decades of research, go programmers never approached consensus on an evaluation function. AlphaGo's value network has to be an improvement on them, but, as moha indicates, it still needs to be supplemented by Monte Carlo rollouts.

I've been wondering about rollouts in a tangential way.

Assuming I've understood how the whole thing works, I think it's not contentious to say that both humans and AG rely on intuition/neural networks. The result for AG is a bank of candidate moves which it considers further by means of rollouts (i.e. looks deeper tactically). Superficially humans do the same, but amateurs, especially in quick games, don't really come up with a list of candidate moves most of the time. Instead, assuming there are features they recognise, they come up with the "shape move" - a single move that they play as a knee-jerk response. There is often no deeper search, and when there is, it is simply of the type "is this safe?" as opposed to "is this candidate move better than that candidate move."

Now we mustn't assume pros play like that, but, if we assume there is a continuum from weak amateurs up to AG that expresses how much candidate moves are explored, can we really assume pros are right at the AG end?

Very many pros, and almost all those who have played AG, are now used to playing fast games. Have they got into the habit of not exploring candidate moves sufficiently? I'm quite sure they look very deeply at certain moves (conceivably even deeper than AG), but are they working with a much shorter list of candidates than AG and, if so, is this because they are too used to playing too quickly? They are Paganinis instead of Mozarts and Beethovens?

My thoughts, obviously still in flux, are heavily influenced by the fact that I am still transcribing 1930s games and I am regularly astounded at how much the style of play (almost everyone's - not just Go Seigen's) then resembles AG. Incidentally, I imagine very, very few modern players, even top pros, will have seen these games, beyond those of Go and Kitani. Almost all the games are commented by both players, and a distinctive feature of the commentaries is how often alternative moves (candidates) were considered. Apart from style, and of course lack of komi, the most distinctive difference between these games and modern ones is time. Time limits then varied between 16 hours and 8 hours. Call it 10 hours each on average, which works out about 5 minutes a move. That means 10 times longer than the ubiquitous 30 seconds a move of today, and ridiculously more than the 10 minutes each mode. Surely with that sort of difference it has to be a different kind of go - better even, as AG might be suggesting? Haute cuisine over fast food?

moha · **#351**

John Fairbairn wrote:

I think it's not contentious to say that both humans and AG rely on intuition/neural networks. The result for AG is a bank of candidate moves which it considers further by means of rollouts (i.e. looks deeper tactically). Superficially humans do the same, but amateurs, especially in quick games, don't really come up with a list of candidate moves most of the time. Instead, assuming there are features they recognise, they come up with the "shape move" - a single move that they play as a knee-jerk response. There is often no deeper search, and when there is, it is simply of the type "is this safe?" as opposed to "is this candidate move better than that candidate move."

Now we mustn't assume pros play like that, but, if we assume there is a continuum from weak amateurs up to AG that expresses how much candidate moves are explored, can we really assume pros are right at the AG end?

Very many pros, and almost all those who have played AG, are now used to playing fast games. Have they got into the habit of not exploring candidate moves sufficiently? I'm quite sure they look very deeply at certain moves (conceivably even deeper than AG), but are they working with a much shorter list of candidates than AG and, if so, is this because they are too used to playing too quickly?

I think humans can never explore candidate moves sufficiently, errors/oversights will always happen. This is why shape and strategy were born - dealing with the uncertainity (unread lines) is the essence. But pro levels are different, real strength needs deep reading. I think there are two reasons for less candidate moves: humans minimax slower, but can choose candidates better. Still human pros rely on strategy for evaluating positions where the reading stops, which corresponds to Alphago's value network.

Alphago is yet different, however. It's search has two levels. For the upper nodes they use their policy net to choose good candidate moves to explore, and they do their search methodically. This, as you noted, is similar to human play. But the lower nodes - the rollout part - is unique. Rollouts explore to the end, use no evaluation function so are free from strategic beliefs, and only informative as a winning percentage. If you can give a position to a room full of pros, have them play games starting from that point, and after a few days ask how many of the games were won by black, that's good information.

The problem with this is that neural nets are so slow that AG cannot use it's real policy net during rollouts. They use a much reduced version, which means much weaker candidates are used during that phase. This is a major blow for MC which depends on the quality of moves during rollouts (room of pros vs room of beginners). Even with this huge handicap, rollouts are something that humans don't have, and can be more informative than intuition / value nets.

John Fairbairn · **#352**

(Thanks, moha.)

I have several times mentioned AG's play being prefigured in the 1930s. I came across another good example this morning. The first 100 moves are below with my comments attached. We tend to talk about Shin Fuseki, but I think it's important to remember that the new thinking went much deeper than the fuseki alone. In any case, this was 1936, a few years after the Shin Fuseki proper, and its new ideas had had time to deepen.

20: This is, in itself, not Shin Fuseki, perhaps. I was surprised by this move and even more surprised to see it had no comment (there was plenty of comment on the joseki just before). My conclusion was that it's an ijime-preventing move (see an earlier thread on this topic) as White's shape with a Black stone around 20 is uncomfortably exposed to a placement at O18, but it's also surprisingly effective at remotely controlling the upper left corner (reduces Black's options at the very least). But, overall, the main instantaneous impression is that Black's outside wall plus a bit of territory looks far superior given they have played an equal number of stones. However, AG-like, White has sensed that Black's thickness is not all that thick.

21: And Black maybe agrees, feeling obliged to take the side rather than a corner.

24: AG's favourite shimari - not so unusual in those days and often played in the more usual order.

26: Again uncommented! Looks low, but we've seen AG play unusually low moves.

46: Definitely an AG shoulder hit!

54: Giving up territory on the 4th line, supposedly bad in itself, but even if you assume White senses compensation in the centre, you have to admit that in this position he must have a touch of extra-sensory perception. As per my argument above, one factor must be that each player had 11 hours thinking time. At a more mundane level, however, it was also meant as a ladder breaker, as Maeda explains in his comments. He added that it was actually a misread and a very bad move - not because of what happened in the lower right, or the ladder, but because of the complex tactics/aji in the upper left.

56: Another shoulder hit.

59: A surprising attachment, certainly reminiscent of Go Seigen, and maybe of AG. But not commented, so maybe it was superobvious to a pro.

90: Maeda was known as the God Of TsumeGo, and this pattern belongs to the standard comb formation shapes (typically is a ko). But he confessed he overlooked Black 91. Would AG overlook this sort of early move, do you think?

100: An interesting tewari question: can we assume some of the stones in Black's baguette are now inefficient?

Black won the game by 5 but, as there was no komi, perhaps we can say it was even stevens and White's AG-like play did work.

EdLee · **#353**

Hi Bill,

(Off topic):

Quote:

100: An interesting tewari question: can we assume some of the stones in Black's baguette are now inefficient?

For some time now I've wondered about the limitations of tewari.
Happy to find out you've written about it -- HowToLieWithTewari.

Bill Spight · **#354**

EdLee wrote:

Hi Bill,

(Off topic):

Quote:

100: An interesting tewari question: can we assume some of the stones in Black's baguette are now inefficient?

For some time now I've wondered about the limitations of tewari.
Happy to find out you've written about it -- HowToLieWithTewari.

Actually, How to Lie with Tewari is Charles Matthews' brainchild.

As for John's question, I don't think that the effects of the "baguette" are obvious at this point. After all, at the end of the game each stone exerts less than 1 pt. of influence. It is then hard to tell, maybe impossible, what their influence was earlier.

EdLee · **#355**

Hi Bill, I meant that you contributed to that page.

Bill Spight · **#356**

AlphaGo vs AlphaGo Game 33

Click Here To Show Diagram Code: [go]$$Bcm11 Pincer $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O B . . . . . . . . . . . . . . . | $$ | . . B B . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . 2 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 1 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . . . a . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Instead of replying at "a" White plays a two space high pincer. This play also aims at the :bc:

stones. I like it.

Click Here To Show Diagram Code: [go]$$Bcm13 Go Seigen style $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . O . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . 2 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . , . . . | $$ | . . . . . 1 . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black plays a double approach, and White replies with a capping play, Go Seigen style.

Click Here To Show Diagram Code: [go]$$Bcm15 Even steven $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . O . . . . . . . . . . . . . | $$ | . . O , . . . . . , . . . . . X . . . | $$ | . . O B . . . . . . . . . . . . . . . | $$ | . . B B . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 5 7 9 . . . . , . . . . . , . . . | $$ | . . 6 O 8 . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . 2 O 4 . . . . , . . . . . , . . . | $$ | . . 1 3 . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black jumps into the corner and then extends from the :bc:

stones to divide the left half of the board equitably.

Click Here To Show Diagram Code: [go]$$Wcm24 AlphaGo special $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . 9 . . . . . | $$ | . . . O . O . . . . . . . 6 7 5 3 . . | $$ | . . O , . . . . . , . . . . 8 X 4 . . | $$ | . . O X . . . . . . . . . . . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X . . . . , . . . . . , . . . | $$ | . . O O O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . 2 . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . 1 . . | $$ | . . O O O . . . . , . . . . . , 0 . . | $$ | . . X X . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

approaches the bottom left corner and Black plays a two space high pincer. Then :w26:

jumps into the top right corner, AlphaGo style. Black takes sente and plays the kick against :w24:

.

Click Here To Show Diagram Code: [go]$$Wcm34 The fighting begins $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . 3 O . . . . . | $$ | . . . O . O . . . . . 4 2 X O O O . . | $$ | . . O , . . . . . , . . . 1 X X X . . | $$ | . . O X . . . . . . . 6 . 5 . . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X . . . . , . . . . . , . . . | $$ | . . O O O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X . O . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . O O O . . . . , . . . . . , X . . | $$ | . . X X . X . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

With the atari, :W34:, the fight begins in earnest.

Before, I have shown you AlphaGo innovations, but this opening, while not exactly conventional, is well within the realm of human play, up until the 3-3 invasion. And now, OC, humans are playing that.

Why show something so ordinary?

Well, it shows a different way that AlphaGo handles the left side, and it is also a prelude to the quiz in my next note.

Bill Spight · **#357**

Human or AlphaGo?

The next diagrams come from the AlphaGo (Master) vs. human games this past winter. They all show pincers. The question is, who played the pincer, AlphaGo or human?

Click Here To Show Diagram Code: [go]$$Bcm7 Three space high pincer $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . O . . . . | $$ | . . . , . . . . . , 1 . . . . , X . . | $$ | . . X . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]