#177 The Intrepid vs. uranther

The Intrepid · Post by **The Intrepid** » Thu Sep 13, 2012 4:34 pm

Comments regarding :w13:

:

Anyone who’s ever done nonfiction writing or scientific/mathematics research will likely have experienced what writers call the “O, sh*t!” moment. Out of respect for the English language and in the interest of protecting the innocence of lifein19x19.com forum goers, I will instead refer to this as the “Holy Excrement!” event. Such an event occurs whenever people find out their argument or research was completely wrong or when the writing or research was already completed by someone else. In writing, that’s not the end of the world. The writer just goes on to add a sentence like “even though so-and-so already argued this exact point, it was important to reiterate this because …” and everything is fine. In scientific or mathematics research, this means the person just lost a few years of his or her life.

Anyway, after making :w11:

, I experienced just this kind of a “Holy Excrement!” event. I came to realize that I had completely missed a strong possibility for Black. Specifically, while I saw that Black can play at :b1:

, I failed to realize that the simple connection of :b3:

is sente.

Click Here To Show Diagram Code: [go]$$Bc Prisoners: $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . 1 O O O . . | $$ | . . . . . . . . . . a O O 2 X O . X . | $$ | . . . X . . . O . O b X X X 3 X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Next, Black threatens to play at “a,” which instantly puts White to the test. Should White play at "a" (strengthening the three White stones and making it easier to capture the cutting stone :b1:

) or does White have to play at “b” to keep Black stones on the bottom from coming to life? Unfortunately, White “a” seems impossible:

Click Here To Show Diagram Code: [go]$$Wcm4 Prisoners: $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O . . | $$ | . . . . . . . . . . 1 O O O X O . X . | $$ | . . . X . . . O . O . X X X X X O . . | $$ | . . . X . O . . . 5 4 . . O . X O . . | $$ | . . . . . . . . 7 6 . 8 . . 2 O 3 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black group gets at least a ko for life, which is unacceptable for White. Thus, White has to play at “b.” However, Black then has a cornucopia of cutting points to try to exploit:

Click Here To Show Diagram Code: [go]$$Wcm4 Prisoners: $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O . . | $$ | . . . . . . . . . . M O O O X O M X . | $$ | . . . X . . . O . O 1 X X X X X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . M O M . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

In fact, Black can take immediate profit by playing :b5:

:

Click Here To Show Diagram Code: [go]$$Wcm4 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . c . | $$ | . . . X . . . . . O . . . O O X . . . | $$ | . . . . . . . . . . . . X . X . . d . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O 2 . | $$ | . . . . . . . . . . . O O O X O 3 X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White is forced to connect at :w6:

, so Black gains around 10 points (compared to if White played at :b5:

) and secures additional eye-space for his right group. Next, Black can play near the edge (at “c,” for instance) to secure eye-space for another eye or run into the center as in the game. Thankfully for White, it does not seem that Black can tenuki. If White plays at “d,” Black group does not have enough space for two eyes--at least based on the variations I looked at, so far. Therefore, White would be able to either deny Black’s group access to the center (helping White to create territory there) or else continue pressuring the two weak Black groups.

Here are some variations which show that White does not die immediately, despite the multitude of cutting points. First, if Black tries to save the bottom group, White proceeds in the following manner:

Click Here To Show Diagram Code: [go]$$Bcm5 $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O . . | $$ | . . . . . . . . . . . O O O X O . X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . 3 4 5 O . X O . . | $$ | . . . . . . . . . . . 6 . . 1 O 2 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bcm5 $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O . . | $$ | . . . . . . . . . . . O O O X O . X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . 5 3 . O . X O . . | $$ | . . . . . . . . . 6 4 . . . X O O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bcm7 $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . X O O O . . | $$ | . . . . . . . . . . . O O O X O . X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . 4 2 3 O . X O . . | $$ | . . . . . . . . . . 6 1 5 . X O O . . | $$ | . . . . . . . . . . . 7 . 8 . . . . . | $$ ---------------------------------------[/go]

Second, White does not need to fear an immediate cut at L5:

Click Here To Show Diagram Code: [go]$$Bcm5 $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . . O O X . . . | $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . 7 . . . X . . | $$ | . . . . . . . . . . . 6 5 2 . X . . . | $$ | . . X . . . . . . 8 . 4 3 X O O O X . | $$ | . . . . . . . . . 9 1 O O O X O O X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

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

Incidentally, White cannot play :w14:

at J5 as then the bottom group lives:

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

Click Here To Show Diagram Code: [go]$$Bcm21 $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . X . . . X . . | $$ | . . . . . . . . . . . O X O . X . . . | $$ | . . X . . . . . . O . O X X O O O X . | $$ | . . . . . . . . O X X O O O X O O X . | $$ | . . . X . . . O O O O X X X X X O . . | $$ | . . . X . O . . . X X O 1 O . X O . . | $$ | . . . . . . . . . 5 4 2 3 . X O O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

In the worst case scenario, if Black cuts at L5, White can always save himself by killing the bottom group:

Click Here To Show Diagram Code: [go]$$Bcm5 $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . . O O X . . . | $$ | . . . . . . . . . . . . X . X . . . . | $$ | . . . . . . . . . . . . 7 . . . X . . | $$ | . . . . . . . . . . . 6 5 2 . X . . . | $$ | . . X . . . . . . . . 4 3 X O O O X . | $$ | . . . . . . . . . . 1 O O O X O O X . | $$ | . . . X . . . O . O O X X X X X O . . | $$ | . . . X . O . . . . . 8 . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Naturally, this semedori is a solution of last resort. White would lose points (by having to place stones in his own territory) while Black would get to strengthen himself on the outside.

With all of the above remarks in mind, one may wonder whether :w11:

was a good move, an overplay, or a mistake. I’m not sure. It seems to me that, despite giving Black a chance to complicate the game and gain around 10 points in sente, White can hope to gain just as much or more from continuing to attack Black’s groups. That said, with the current game situation in mind--i.e. with White enjoying a solid lead--the safest way to play would have been to play :w11:

at S6. Black would need to respond to this so, after taking a profit of around 10 points in sente, White could proceed to invading Black’s left moyo. Nevertheless, taking the aspect of risk aside, :w11:

as played in the game might very well be a better move, objectively speaking.

This is why I chose to continue the attack with :w13:

. WS6 would be an admission of having made a mistake on the previous move and would result in a small loss for White coming from the exchange of :w11:

for

. May the conflagration of White’s attack be never extinguished!

uranther · Post by **uranther** » Tue Sep 18, 2012 2:04 am

Click Here To Show Diagram Code: [go]$$Bcm12 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . 2 O O X . . . | $$ | . . . . . . . . . . . . X 1 X . . . . | $$ | . . . . . . . . . 3 . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The Intrepid: Sorry for taking so long on my moves -- I have a lot going on recently.

The Intrepid · Post by **The Intrepid** » Tue Sep 18, 2012 1:59 pm

Click Here To Show Diagram Code: [go]$$Bcm14 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . 2 . X X X . . . . | $$ | . . . . . . . . . 1 . . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Don't worry about a thing, uranther. I care about the quality of your moves, not about the length of time it takes you to make them. Besides, I needed a longer think myself.

uranther's move is good as far the right group is concerned. If I try to cut :b14:

from its brethren, the cutting stone will be captured in a net or the right group will connect to the top group. However, uranther's move also allows me to connect my center stone to my group on the right and it lets me reinforce some of the weaknesses in my bottom group. The expected sequence is the following:

Click Here To Show Diagram Code: [go]$$Bcm14 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . a . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O 8 . . . . . O . . . | $$ | . . b b . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . 2 4 X X X . . . . | $$ | . . . . . . . . . X 3 5 7 . . . X . . | $$ | . . . . . . . . . . . . 6 . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Next, "a" and "b" are miai for White.

I should add that, with Black's right group escaping into the center, White will no longer be able to get any territory in the middle. However, I was leaning more toward destroying Black's territory on the left than toward trying to cultivate a central moyo, anyway. The center was simply too open for my liking.

uranther · Post by **uranther** » Fri Sep 21, 2012 11:35 am

Click Here To Show Diagram Code: [go]$$Bcm14 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . 2 . X X X . . . . | $$ | . . . . . . . . . 1 3 . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This

seems obvious and consistent, although I didn't anticipate :w2:

from lack of deeper analysis.

I think White almost has to play to cut:

Click Here To Show Diagram Code: [go]$$Bcm1 Next few moves probably like this. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . 2 5 X X X . . . . | $$ | . . . . . . . . . 1 3 4 . . . . X . . | $$ | . . . . . . . . . . . 6 . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

We're about to get into a nasty fight in the center! Of course, it favors White because of Black's weak position.

Click Here To Show Diagram Code: [go]$$Bcm1 Maybe this way is my best bet $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O 5 7 O O O X . . . | $$ | . . . . . . . . . 6 O 3 X X X . . . . | $$ | . . . . . . . . 8 X 1 2 . . . . X . . | $$ | . . . . . . . . . . . 4 . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After

, then what? I will lose the two stones as the cost to kinda connect and I think this is okay. But the fight continues..

Click Here To Show Diagram Code: [go]$$Bcm1 I can atari the other way, but it looks bad $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . 5 4 . X O . . . . | $$ | . . . X . . . . 6 O 2 3 O O O X . . . | $$ | . . . . . . . . . 1 O X X X X . . . . | $$ | . . . . . . . . . X X O . . . . X . . | $$ | . . . . . . . . . . . O . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bcm1 And I don't want to push White into my group $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . 8 3 X . . O . . | $$ | . . . . . . . . . . 7 4 2 X O . . . . | $$ | . . . X . . . . . O 5 1 O O O X . . . | $$ | . . . . . . . . . 6 O X X X X . . . . | $$ | . . . . . . . . . X X O . . . . X . . | $$ | . . . . . . . . . . . O . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The Intrepid · Post by **The Intrepid** » Sat Sep 22, 2012 3:08 am

Click Here To Show Diagram Code: [go]$$Bcm16 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O 2 X X X . . . . | $$ | . . . . . . . . . X 1 . . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Although I ended up following the variation I cited in my previous post, I decided to take the time to analyze the cut at M8 once more.

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O M . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . W . 4 O O O X . . . | $$ | . . . . . . . . . . W 2 X X X . . . . | $$ | . . . . . . . . . B B 1 . . . . X . . | $$ | . . . . . . . . . . . 3 . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The idea here would be not to keep trying to separate Black’s right and top groups, but instead to separate the marked Black stones in the center and to try to kill them. If this were accomplished, White would end up with territory in the center.

However, this idea does not seem to work. Firstly, these stones are immensely hard to kill. Secondly, Black could play lightly with the stones, trading them for central territory of his own. Thirdly, White’s marked cutting stones are very weak and White still has the cut at K13 to worry about. In fact, if Black were to play there, White’s stones in the area would fall under severe attack. For these reasons, White should not attempt to cut Black at M8. The move in the game is safer and stronger.

uranther · Post by **uranther** » Sun Sep 23, 2012 5:26 pm

Click Here To Show Diagram Code: [go]$$Bcm16 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O 2 X X X . . . . | $$ | . . . . . . . . . X 1 3 . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I have to protect against White's move, but he doesn't need to follow up.

Click Here To Show Diagram Code: [go]$$Bcm1 The net works $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X 9 . . . | $$ | . . . . . . . . . X X 1 2 4 8 . X . . | $$ | . . . . . . . . . . . . 3 6 5 X . . . | $$ | . . X . . . . . . . . . . 7 O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White will probably attack my top group's shape or tenuki. I am behind in tempo and it hurts.

Click Here To Show Diagram Code: [go]$$Wcm1 White continues an attack elsewhere $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O b . . . . . O . . . | $$ | . . . . . . . . . X . a . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . c . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X . . . . X . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I have no idea where White will go, but it will probably be painful!

The Intrepid · Post by **The Intrepid** » Mon Sep 24, 2012 3:31 am

Click Here To Show Diagram Code: [go]$$Bcm18 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X 1 . . . . X . . | $$ | . . . . . . . . . . . . 2 . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Obviously, the cut does not work:

Click Here To Show Diagram Code: [go]$$Wc $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 1 3 . . X . . | $$ | . . . . . . . . . . . . 2 . 4 X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

White shouldn't play at O7, either, as Black can respond with N7, which threatens L5:

Click Here To Show Diagram Code: [go]$$Wc tenuki $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X . . . . X . . | $$ | . . . . . . . . . . . . 2 1 . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . 4 O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

While not immediately deadly, there is simply no reason for White to allow Black to have this threat.

The point of exchanging WN7 for BN8 is that White will now be able to respond to BO6 at O7 and not at O5 as before:

Click Here To Show Diagram Code: [go]$$Wc $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 2 . . . X . . | $$ | . . . . . . . . . . . . 1 5 . X . . . | $$ | . . X . . . . . . . . . . 4 O O O . . | $$ | . . . . . . . . . . . O O C X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

uranther · Post by **uranther** » Tue Sep 25, 2012 5:41 pm

Click Here To Show Diagram Code: [go]$$Bcm18 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O . . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X 1 3 . . . X . . | $$ | . . . . . . . . . . . . 2 . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The Intrepid · Post by **The Intrepid** » Wed Sep 26, 2012 11:54 pm

Click Here To Show Diagram Code: [go]$$Bcm20 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O 2 . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 1 . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Sorry for the delay. I got bogged down by some real-life stuff.

I had quite a bit of a think here. I was trying to make O15 work without the preemptive move at K13. Unfortunately, I can's seem to get anything substantial out of it if Black responds at K13.

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . W . . . . . . . . . . . | $$ | . . . X . W . X W W . W . X . . O . . | $$ | . . . X . X X X W C W X . . . X . O . | $$ | . . . . . . . O X W X . . 1 . . . . . | $$ | . . . X . . X X X W . . X . X X O . . | $$ | . . . ? ? ? ? Q Q 2 . . . . . O . . . | $$ | . . . ? ? ? ? . . X . . . X . . O . . | $$ | . . . ? ? ? ? . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

Black, instead of trying to live inside, would strongly threaten to capture the :wt:

stones and, therefore, to escape. If successful, Black could end up making much territory in the shaded area. In addition to this, White's top group :wc:

could end up getting attacked. Thus, an immediate WO15 appears to be an overplay for White. Naturally, it is easy for both players to go wrong (especially for Black), so I could hope for a mistake from uranther. Yet, objectively speaking, I don't think the move is the best one available to me in the given position--hence the move at K13. This move strengthen's White's top group (it can run, if need be and White does not need to connect at K16 any time soon, which is a problem in many variations when trying to attack Black's top group). Also, the move makes it easier to invade Black's moyo on the left and it prevents Black from forming territory in the shaded area. Finally, and perhaps most importantly, I do believe the move to be absolute sente. If Black fails to protect his top group, it could well end up dying (which is worth 60+ points). In other words, I got to make a very useful move in sente, while uranther is forced to remain on the defensive. That said, I better make sure that my followup invasion on the left succeeds, because my advantage is largely equivalent to the amount of points I can reduce Black's moyo by on the left. However, before doing the invasion, I may first resume attacking Black's right group, if I can do so in sente.

uranther · Post by **uranther** » Mon Oct 01, 2012 1:52 pm

Click Here To Show Diagram Code: [go]$$Bcm20 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O 2 . . . . . O . . . | $$ | . . . . . . . . . X . 3 . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 1 . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Sorry for the delay. I got bogged down by some real-life stuff.

Don't I feel silly! It's hard moving across the country, starting a business and doing everything else too

Recently I've been visiting the Go Club in Denver. Players of all ages (15k-1d) attend the club meetings -- each lasting 4-5 hours -- held in a local & organic café powered by the Wind and Sun. Members give lessons over recent game scenarios; books are consulted for best practices and josekis; and games are deliberated over by the spectators and players. Last time we watched a 1d (who has at least been to the 2004 US Go Congress, judging from the shirt) overwhelm his elder 1k opponent. The match turned into a giant fight which spread across the board, and in the end they were trading prisoners because all the ko fights exhausted their stones. Interesting match! Needless to say, I learn a lot every time I go -- and I drink delicious café beverages while I'm at it!

Seeing White's move, I thought the circled Black stone below suddenly looks lonely.

I looked at a before, although it doesn't do much against the counter-attack at x (the fight favors white, usually ending in a split of my group).

The game move is where White might have played to split me apart and attack my cramped group.

Click Here To Show Diagram Code: [go]$$Bcm1 Trying not to get crushed $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X b . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O 2 . x . . . O . . . | $$ | . . . . . . . . . B . * . X . . O . . | $$ | . . . . . . . . . . . a . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 1 . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

b is too slow and doesn't prevent a harsh attack. I can give up a stone...

Click Here To Show Diagram Code: [go]$$Bcm1 Trying not to get crushed $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X 5 . . X . O . | $$ | . . . . . . . O X O X 4 6 7 . . . . | $$ | . . . X . . X X X O . 8 X . X X O . . | $$ | . . . . . . . O O 2 . . 9 . . O . . . | $$ | . . . . . . . . . X . 3 . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X 1 . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The Intrepid · Post by **The Intrepid** » Fri Oct 05, 2012 12:53 pm

uranther wrote:Recently I've been visiting the Go Club in Denver. Players of all ages (15k-1d) attend the club meetings -- each lasting 4-5 hours -- held in a local & organic café powered by the Wind and Sun. Members give lessons over recent game scenarios; books are consulted for best practices and josekis; and games are deliberated over by the spectators and players. Last time we watched a 1d (who has at least been to the 2004 US Go Congress, judging from the shirt) overwhelm his elder 1k opponent. The match turned into a giant fight which spread across the board, and in the end they were trading prisoners because all the ko fights exhausted their stones. Interesting match! Needless to say, I learn a lot every time I go -- and I drink delicious café beverages while I'm at it!

That sounds awesome! I'll be sure to check it out when I'm in town.

It may take me some more time to make my next move. Tough decision.

I am trying to decide between "a" and "b".

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X b . . X . O . | $$ | . . . . . . . O X O X . . a . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . |[/go]

I thought I found a way for Black to live after "a", but now I found a flaw in that variation. "b" looks enticing, as well. A difficult choice ahead.

In any case, even though uranther correctly recognized that his top group is in imminent danger, I don't think his move was the best way to reinforce this group. My right and top groups still have weaknesses, so it would have been better for Black to play a move which would seek to exploit these weaknesses--in addition to protecting his group. I haven't looked too closely at the various possibilities but "c" and "d" seem interesting:

Click Here To Show Diagram Code: [go]$$ $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O c X . d O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . . . X . . O . . |[/go]

Instead, uranther seems to be trying to run! Running isn't the best idea for him, however. First of all, I don't think it's possible to run just yet.

Click Here To Show Diagram Code: [go]$$Bc Black can't protect both e and f simultaneously $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O 4 . . . . O . . . | $$ | . . . . . . . . 1 X 2 X . X . . O . . | $$ | . . . . . . . . . e 3 f . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

Click Here To Show Diagram Code: [go]$$Bc Black gets cut off with either g or h $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X 1 X . X . . O . . | $$ | . . . . . . . . g . . . . X O . . . . | $$ | . . . X . . . . h O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

Moreover, if he does end up being able to run, I could get to play the following:

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . 1 O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . 3 . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . |[/go]

This would cut off Black's right group and would also give me additional strength for invading Black's moyo on the left.

Incidentally, Black's right group can live locally via the following variation, so it is not critical for this group to have the ability to run:

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

In any case, following uranther's last move, I expect to gain a profit. The only question is whether that profit will take the form of my killing his entire top group or not. Time for some more reading. :study:

The Intrepid · Post by **The Intrepid** » Sun Oct 07, 2012 11:20 am

Click Here To Show Diagram Code: [go]$$Bcm22 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X 2 . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . 1 . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

In addition to the two possibilities I mentioned previously, I also looked at the following move:

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . 1 . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . 3 X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This move not only prevents Black's top group from running, but also threatens to kill Black's right group with :w3:

if Black fails to respond to :w1:

. However, I decided to wait with this move. It will still be there after I'm done with Black's top group. In addition to this, if uranther tries to run with his top group, I may very well end up playing :w1:

naturally.

Let me return to a diagram I mentioned in my previous post:

Click Here To Show Diagram Code: [go]$$Bc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O 4 . . . . O . . . | $$ | . . . . . . . . 1 X 2 X . X . . O . . | $$ | . . . . . . . . . e 3 f . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

Here, I concluded that Black gets cut off because e and f can't be protected simultaneously. However, I should not play like this as this carries unnecessary risk for me:

Click Here To Show Diagram Code: [go]$$Bcm5 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X . . . X . O . | $$ | . . . . . . . O X O X . . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O O . . . . O . . . | $$ | . . . . . . . . X X O X . X . . O . . | $$ | . . . . . . . 3 . 2 X . . X O . . . . | $$ | . . . X . . . . . O . 1 O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

White's center stones get separated and White needs to be extremely careful. However, I have better options available to me than this if uranther tries running with his top group.

Finally, as far as the choice between the move in the game and the alternative I was suggesting earlier (at O15), Black lives in both cases. If I played O15, Black has the following:

Click Here To Show Diagram Code: [go]$$Wc $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 2 X . . O . . | $$ | . . . X . X X X O . O X 4 . . X . O . | $$ | . . . . . . . O X O X 3 . 1 . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . |[/go]

Next, either

Click Here To Show Diagram Code: [go]$$Wcm5 stone saves $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O X X . . O . . | $$ | . . . X . X X X O . O X X . . X . O . | $$ | . . . . . . . O X O # O 1 O . . . . . | $$ | . . . X . . X X X O 2 . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . B . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . |[/go]

or

Click Here To Show Diagram Code: [go]$$Wcm5 a and b are miai for Black $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . 3 a . 6 . 5 . . | $$ | . . . X . O . X O O . O X X . 4 O . . | $$ | . . . X . X X X O . O X X . b X . O . | $$ | . . . . . . . O X O C O 2 O . . . . . | $$ | . . . X . . X X X O 1 . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . |[/go]

Black lives after :w23:

(the move in the game), as well, but the move nets me a few more points than O15 does. That said, O15 leads to more complicated variations. Therefore, if I were behind in the game and needed to kill something big to win, I would play O15. However, overplays are not required here.

uranther · Post by **uranther** » Mon Oct 08, 2012 8:37 am

Click Here To Show Diagram Code: [go]$$Bcm22 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X 2 . . X . O . | $$ | . . . . . . . O X O X 3 . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . 1 . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bcm1 If I don't connect, I'll quickly run out of eye-space. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 1 X . . O . . | $$ | . . . X . X X X O . O X O . . X . O . | $$ | . . . . . . . O X O X 2 . . . . . . . | $$ | . . . X . . X X X O 4 3 X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I think White should connect:

Click Here To Show Diagram Code: [go]$$Bcm1 Maybe White will attack like this? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 3 X 2 4 O . . | $$ | . . . X . X X X O . O X O 5 . X . O . | $$ | . . . . . . . O X O X 1 . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bcm1 If I respond to it, he'll push me around $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 2 X . . O . . | $$ | . . . X . X X X O . O X O 3 . X . O . | $$ | . . . . . . . O X O X 1 4 6 7 . . . . | $$ | . . . X . . X X X O . 5 X 8 X X O . . | $$ | . . . . . . . O O O . . . . 9 O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

So I think I should respond nearby with a counter-attack.

Click Here To Show Diagram Code: [go]$$Bcm1 Maybe something like this to get eye-space at the top. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . 7 . 5 4 6 . . | $$ | . . . X . O . X O O . O 2 X . 3 O . . | $$ | . . . X . X X X O . O X O . . X . O . | $$ | . . . . . . . O X O X 1 . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

The Intrepid · Post by **The Intrepid** » Mon Oct 08, 2012 5:41 pm

Click Here To Show Diagram Code: [go]$$Bcm24 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 2 X . . O . . | $$ | . . . X . X X X O . O X O . . X . O . | $$ | . . . . . . . O X O X 1 . . . . . . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

uranther made his move unexpectedly quickly. This indicates that he might not have given much thought to sacrificing the ataried stone. I believe he should have. If he played the following instead, his group should not have had too much difficulty living:

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

Now, even though Black's group should still be able to live, the task of doing so will be difficult. Even if the group survives, I expect to gain a larger profit of points than I did a move ago.

If I played the following instead of the move in the game, uranther could, once more, choose to sacrifice the few stones and live:

Click Here To Show Diagram Code: [go]$$Wc (Edit: corrected ) $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O . X . . O . . | $$ | . . . X . X X X O . O X O 4 . X . O . | $$ | . . . . . . . O X O X X 1 2 . . . . . | $$ | . . . X . . X X X O 5 3 X . X X O . . | $$ | . . . . . . . O O O . 6 . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . |[/go]

This would represent a nice profit for me in sente, but I hope to gain more ... much more! Mua-ha-ha-ha-ha-ha-ha! :twisted:

... Ahm.

uranther · Post by **uranther** » Thu Oct 11, 2012 7:15 am

Click Here To Show Diagram Code: [go]$$Bcm24 Prisoners: $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . X . O . X O O . O 2 X . . O . . | $$ | . . . X . X X X O . O X O . . X . O . | $$ | . . . . . . . O X O X 1 . . . . 3 . . | $$ | . . . X . . X X X O . . X . X X O . . | $$ | . . . . . . . O O O . . . . . O . . . | $$ | . . . . . . . . . X . X . X . . O . . | $$ | . . . . . . . . . . . . . X O . . . . | $$ | . . . X . . . . . O . . O O O X . . . | $$ | . . . . . . . . . . O O X X X . . . . | $$ | . . . . . . . . . X X X X . . . X . . | $$ | . . . . . . . . . . . . O . . X . . . | $$ | . . X . . . . . . . . . . . O O O . . | $$ | . . . . . . . . . . . O O . X O . X . | $$ | . . . X . . . O . O . X X X . X O . . | $$ | . . . X . O . . . . . . . O . X O . . | $$ | . . . . . . . . . . . . . . . O . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Life In 19x19

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