Life In 19x19

About move 83 versus Charles, when I wandered over to have a look my intuition was black j10 or j9. If white tries to connect his 2 stones you can either cut or shape attack the whole thing. Maybe a bit risky if you go for the latter and don't kill. Your way of swallowing g7 did seem rather conservative, but if it's enough to win it's simpler. And yes g7 huge mistake: I was thinking you might even spend a gote for the thick f5 (and previously surprised g3 left unplayed for so long) aiming at corner shenanigans so it was a gift for him to give it to you for free.

P.S. isn't e4 tesuji instead of d6: if block then you d5 and have a double atari. Maybe not so amazing seeing as he can connect to c12 (and g4 not so good after, but I don't think it's so amazing if you don't get g3), but you see that move with this side invasion sequence.

j9/10 looks interesting. It's the sort of move I might notice on a computer screen, but not on a real board.

added e4 commentary. I'm not sure, perhaps I could have considered it more. In the game W did get a concerning amount of territory, especially with G3, and while B was very thick, B would have to try to kill an invasion.

The top right corner in the game vs. Groenen is interesting.

Click Here To Show Diagram Code

[go]$$Bcm49 Black gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . O 2 1 3 X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

Black played B149 - B151 in the game, gaining 3 points.

Click Here To Show Diagram Code

[go]$$Wc White gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . O . 1 . X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

This gote by White gains 3 points.

Click Here To Show Diagram Code

[go]$$Wc White alternate gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . 5 1 4 . |
$$ | . . X O O . . . . . . . . O . 3 2 X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

So does this gote sequence.

Click Here To Show Diagram Code

[go]$$Wc White loses 1/3 pt.
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . b a 2 c . |
$$ | . . X O O . . . . . . . . O 3 . 1 X d |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

This gote sequence loses 1/3 pt., on average, by comparison, gaining only 2 2/3 pts. instead of 3 pts. Next, a play by either player at "a" gains 2 2/3 pts.; Black can jump to "b" if she's not afraid of the throw-in ko. The 1/3 point is based upon the possibility that White gets "a", "c", and "d", which leaves a 1/3 point ko in the corner.

Click Here To Show Diagram Code

[go]$$Bc Black sente
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . c b . . . |
$$ | . . X O O . . . . . . . . O . . a X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

The original position is ambiguous, because Black can also play a 3 pt. sente at "a", "b", or "c". "c" could also be ambiguous, depending on White's response.

dhu163 wrote:j9/10 looks interesting. It's the sort of move I might notice on a computer screen, but not on a real board.

That's one reason I like to stand up and wander around for a bird's eye view of the board (plus I'm fidgety and don't like sitting still concentrating for hours).

Bill: Yes it is interesting.

You say B gains 3 points, I normally say it is worth 6 points. I suppose we mean the same thing.

I can agree that in general your 3rd diagram is marginally better for white than the 4th, but by 1/6. I think you mean that after white a, then c is worth 2 2/3, so therefore a is worth 3 points with a 2 2/3 gote follow up, and therefore is worth 4 1/3 (instead of the 5 I first wrote down). The 3rd diagram is equivalent to if W gets a and B gets c, so this is better by (3- 2 2/3)/2 = 1/6.

However my original point, backed up by feeling (no analysis) was that in the game position, sente was important, and it would be a good idea to play the tight block R18, as this leaves a big move at a. Since B is under pressure to continue at a, and then W has gained locally in sente already

I think however that it is hard to say which of the 3rd or 4th diagrams is better. The 3rd diagram R19 makes the follow up at 4 even bigger (worth 3 1/3+2 2/3=6) and B is under more pressure to play there. So B is likely to respond, and then W can tenuki instead of 5. However, it is harder for W to tenuki now as that will lose 1/3 point compared to diagram 4. I've changed my mind a few times now, and my conclusion now is that locally there is "0 points" between them, but diagram 3 leaves large follow ups, so it really depends on the rest of the board.

On the other hand the 2nd diagram simply leaves no follow up and no options, and in that sense is unconditionally worse than diagram 3. But in most cases it leads to the same result as diagram 3, so there is "0 points" between them.


In summary, diagram 2 is simple and in general won't lose you points. But depending on the remaining possible endgames, trying to take sente may be better? Endgame can be confusing.


A long time later ...:
I've just spent too long thinking about this, and couldn't see any way for a scenario where leaving behind a bigger follow up (say value A if you play next and B if they play next) is better than just taking than the average point value ( (A+B)/2) if that is an option. Perhaps that should be a theorem. If so, then you've helped me fix a hole in my intuition. And if so, my above commentary is rubbish. diagram 2 is always optimal locally.

Uberdude wrote:

dhu163 wrote:j9/10 looks interesting. It's the sort of move I might notice on a computer screen, but not on a real board.

That's one reason I like to stand up and wander around for a bird's eye view of the board (plus I'm fidgety and don't like sitting still concentrating for hours).

That seems a good idea. There still remains an annoying asymmetry between what I can see for my own moves and my opponent's moves. Too often I notice my weaknesses much more than my opponent's. ie. The set of moves I feel are good for my opponent are different to the set of moves I would feel are good if I were in my opponent's shoes. It's not very rational for an objective game of go.

That seems a good idea. There still remains an annoying asymmetry between what I can see for my own moves and my opponent's moves.

People say that to me all the time. Glad to know I'm not alone in it.

I just had a spectacular game in the BGA online league. Sacrificing 4 stones on the top left for a ko was so cool.

The comments are all from the post game review

various analysis ideas

Sorry for taking so long to respond.

dhu163 wrote:Bill: Yes it is interesting.

You say B gains 3 points, I normally say it is worth 6 points. I suppose we mean the same thing.

Right.

I can agree that in general your 3rd diagram is marginally better for white than the 4th, but by 1/6.

I’ll explain in more detail below.

Click Here To Show Diagram Code

[go]$$Bc Original position
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . O . . . X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

Here is the original position. Let’s evaluate it using a couple of sente sequences.

Click Here To Show Diagram Code

[go]$$Bc Sente sequences
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . C 6 3 7 C C |
$$ | . . X O O . . . . . . . . O 4 2 1 X C |
$$ | . X X O . . . . . . . . . O B O O X C |
$$ | X O O O . O O . . O . . . . O X X C C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

- is a sente sequence, and later so is - . We can count 3 points for White, the marked point plus the captured stone and eye, and 6 points for Black, all marked. The net count is 3 pts. for Black.

Next let’s look at the game result after Black’s gote.

Click Here To Show Diagram Code

[go]$$Bc Black gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O O . . . . . . . . O 2 1 3 X . |
$$ | . X X O . . . . . . . . . O B W W X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

To evaluate this we can do sagari-sagari on the edge and let Black take the stones and White take back.

Click Here To Show Diagram Code

[go]$$Bc Evaluation
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . C O X C C C |
$$ | . . X O O . . . . . . . . O O X X X C |
$$ | . X X O . . . . . . . . . O . O . X C |
$$ | X O O O . O O . . O . . . . O X X C C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

White gets 3 pts., 1 for the marked point and 2 for the captured stones. Black gets 9 pts., 7 for the marked points and 2 for the captured stones. The net count is 6 pts. for Black. Black has gained 3 pts.

Click Here To Show Diagram Code

[go]$$Wc White gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . C C 5 1 4 C |
$$ | . . X O O . . . . . . . . O C 3 2 X C |
$$ | . X X O . . . . . . . . . O B O O X C |
$$ | X O O O . O O . . O . . . . O X X C C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

White can play this gote sequence. White gets 5 pts. and Black gets 5 pts., for a net count of 0. White has gained 3 pts.

Click Here To Show Diagram Code

[go]$$Wc White gote (II)
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . a . . |
$$ | . . X O O . . . . . . . . O . 1 . X . |
$$ | . X X O . . . . . . . . . O X O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

After either side can gain 1 pt. in gote, starting with a play at “a”. We can evaluate this position with sagari-sagari to get a net count of 0, the same as the previous position. Which gote is better depends upon the rest of the board.

Click Here To Show Diagram Code

[go]$$Wc White gote (III)
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . . 2 . . |
$$ | . . X O O . . . . . . . . O 3 . 1 X . |
$$ | . X X O . . . . . . . . . O B O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

I evaluate the count after as 1/3 for Black. Let’s look at the follow-up plays.

Click Here To Show Diagram Code

[go]$$Bc White gote, Black gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . 4 3 1 X . C |
$$ | . . X O O . . . . . . . . O O . O X C |
$$ | . X X O . . . . . . . . . O C O O X C |
$$ | X O O O . O O . . O . . . . O X X C C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

Black has a gote follow-up with . To evaluate the resulting position, let Black play the sente sequence, - . White gets 2 points and Black gets 5, for a net result of 3 pts. for Black. gains 2 2/3 pts.

Click Here To Show Diagram Code

[go]$$Wc White gote, White gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . . . 1 X . . |
$$ | . . X O O . . . . . . . . O O . O X . |
$$ | . X X O . . . . . . . . . O . O O X . |
$$ | X O O O . O O . . O . . . . O X X . . |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

I evaluate the count after as 2 1/3 pt. for White (-2 1/3 for Black). gains 2 2/3 pts. Let’s look at the follow-ups.

Click Here To Show Diagram Code

[go]$$Bc White gote, White gote, Black gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . C C O X 1 C |
$$ | . . X O O . . . . . . . . O O C O X C |
$$ | . X X O . . . . . . . . . O C O O X C |
$$ | X O O O . O O . . O . . . . O X X C C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

After each player gets 5 pts., for a net count of 0. gains 2 1/3 pts.

Click Here To Show Diagram Code

[go]$$Wc White gote, White gote, White gote
$$ ---------------------------------------
$$ | . . X X O . . . . . . . . C C O B 1 . |
$$ | . . X O O . . . . . . . . O O C O X 3 |
$$ | . X X O . . . . . . . . . O C O O X 8 |
$$ | X O O O . O O . . O . . . . O X X 4 C |
$$ | . X O . . O X . X O . . . O . . . . . |
$$ | . X X X . O X X O O . . . . O X . . . |
$$ | . . . . X . X O X . . . . O X X . . . |[/go]

To evaluate the position after , let White play - with sente. Later and the White connection at are miai. White gets 6 pts. for the 4 marked points plus 2 captured stones. Black gets 1 marked point plus 1/3 pt. for the stone in ko. The net count is -4 2/3 (for Black). gains 2 1/3 pts.

thanks for this Bill, it took me a bit of time, but I see what you mean now. And probably diagram 4 is never better.

The language I use for endgame does seem to confuse myself. It comes from pro commentary estimates, and my own understanding with a rough overview of the theory, whereas your system is clearer, comparing everything to a given zero point.

dhu163 wrote:I can agree that in general your 3rd diagram is marginally better for white than the 4th, but by 1/6. I think you mean that after white a, then c is worth 2 2/3, so therefore a is worth 3 points with a 2 2/3 gote follow up, and therefore is worth 4 1/3 (instead of the 5 I first wrote down). The 3rd diagram is equivalent to if W gets a and B gets c, so this is better by (3- 2 2/3)/2 = 1/6.

There is a lot of rubbish in what I wrote here. It should be:

after white a, then c is worth 4 2/3, so therefore a is worth 3 points with a 4 2/3 gote follow up, and therefore is worth 3+ (4 2/3) /2 = 5 1/3 (instead of the 5 I first wrote down). The 3rd diagram is equivalent to if W gets a and B gets c, so it is better by ((4 2/3 )/2- 3)/2 = 1/3.

dhu163 wrote: The language I use for endgame does seem to confuse myself. It comes from pro commentary estimates, and my own understanding with a rough overview of the theory, whereas your system is clearer, comparing everything to a given zero point.

Yes, I do think that the usual method of evaluating plays causes confusion. But this is not my system. It uses what I learned as miai counting, what O Meien today calls absolute counting ( 絶対計算 ).

final pandanet game, and I've gone all season undefeated, playing almost all matches

this game, my play quality was low, or at least my alertness, judgement, reading were all down due to exam prep exhaustion, just relying on feeling. Also my opponent played well, making a nice plan to attack a weak group of mine (I should probably have sacrificed a large group to save that one) and perhaps it should have died. In the end, I thought I was slightly behind, but score estimate says I was ahead, I threatened a slow ko to kill my opponent's corner. Instead he threw the ko in himself, so I took the ko first for free, he played a fake ko threat in time trouble, and I won.

I made a quick commentary.



And a practical way to avoid the complacency vs Andrew Kay is probably to imagine a significant reverse komi, to keep playing good moves, and still challenge my opponent to think, to still leave a high quality game, than some conservative rubbish.

I just had a good pro game study session. Perhaps with uni pressure and computer go, my creative spirit in go has gotten lost, and I've stopped improving.

With computer go, I've fallen for the trap of thinking learning their ideas and techniques will help my go, when I forget how much of a gap I have on the understanding of every move of high level games and every move they notice but don't play. Perhaps it is also that the high level of judgement and intuition of computer go really brings me back to my ideas of the logic of fuzzy concepts and intuition that I found so interesting before in go. But it turns out to have limited value in improving go skill. I need to put more emphasis improving my personal understanding rather than mimicking high level moves when my understanding of lower level moves is insufficient. I've reduced my leela usage to a minimum, and I should try to think more independently of alphago.

At today's go club, I got the chance to think more deeply about pro moves on a real board, guessing the next move, and seeing how confusing they are, and how big the gap is. Normally I just skim games without thinking too much.

I've looked at the first 30 moves quite in depth and no more. The file size is bigger than my average self-commentary.

Also https://www.youtube.com/watch?v=-yhaEj5ylL0
Lee Changho plays a very cool new move against Lee Sedol in some Korean cup. I can't find the sgf on go4go yet.

not too bad a game. Looked into move 28 in depth.