Life In 19x19

Hi everyone,
I haven't been playing all that regularly lately, and it's been a long time since I had outside input on one of my games- so here is a very close game I played yesterday. Any comments would be greatly appreciated.
I played black.

Hi, zac.

Both sides lost a lot of points in the endgame, playing and answering small moves. For example, :b133: was worth around two points, at a time when many moves (J2, B3, S18, S10, B9) were worth 6-12 points. I guess :b191: was the losing move, losing 1 point (no defense was necessary) and sente when there were still 1 point plays left on the board.

mitsun wrote:I guess :b191: was the losing move, losing 1 point (no defense was necessary) and sente when there were still 1 point plays left on the board.

I think so, too. Also, B193 was a mistake.

Here is an sgf with some variations starting at move 191.

Thank you all,

I picked up quite a few endgame mistakes in my own review of the game. Another game lost by 'obvious' endgame mistakes. Perhaps time to either work through endgame problems, or buy 'the endgame'. Or perhaps time to start counting more carefully and practice keeping focus right until the end of the game ANd, after all, I still had over 7 minutes on the clock + byo-yomi!


A few questions about the possible sequences starting with W8-

When he makes the two space extension (instead of the 'usual' three space) I'm never too sure. Is r15 better, because it puts pressure on his right side group- but how best to play if he then approaches from the top side- o17?

zac wrote:Thank you all,

I picked up quite a few endgame mistakes in my own review of the game. Another game lost by 'obvious' endgame mistakes. Perhaps time to either work through endgame problems, or buy 'the endgame'. Or perhaps time to start counting more carefully and practice keeping focus right until the end of the game ANd, after all, I still had over 7 minutes on the clock + byo-yomi!


A few questions about the possible sequences starting with W8-

When he makes the two space extension (instead of the 'usual' three space) I'm never too sure. Is r15 better, because it puts pressure on his right side group- but how best to play if he then approaches from the top side- o17?

When White plays the restrained move at the marked stone, is one of the major ideas. Black's intent is obviously to prevent White from sliding into the corner. If White responds with (O17), Black most often responds with . After , White mainly plays at "a" or "b" next. However, note that White is making Black stronger, so harassing the two stones on the right side will just be that much more fun later.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . b . . . . |
$$ | . . . . . . . . . . . a . 2 . . . . . |
$$ | . . . O . . . . . , . . 4 3 . X . . . |
$$ | . . . . . . . . . . . . . 5 . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . W . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

The large knight's move below is the main alternative for Black. Note that the small knight's move at "a" does not appear in professional games with this position. (edit: It does appear in situations where the upper left corner has already been developed.) Black anticipates that White will slide in at , in which case Black at "a" will be over concentrated. Among pros, Black almost always plays elsewhere after the , exchange. When the lower left is unfinished, as in the game, would be the logical flow. Neither Black or White should put too much emphasis on playing next in the top right. The left side of the board is more important.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 1 a . . . . . |
$$ | . . . O . . . . . , . . . . . X . 2 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . W . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 3 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Returning to the Black diagonal play in the first diagram. White more often approaches along the top at below rather than at O17. Black normally stabilizes the corner and White extends at the top before Black turns away.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 4 . . 2 . 3 . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . W . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 5 . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Just to add to ez4u's excellent post: if you play the kosumi and white is kind enough to reinforce his right side group with 2 or a, then you can play the large knight's move for a large corner and a good position (it's like you did the big knight first and then white tenuki, then you play kosumi and white defends with jump which is a nice exchange for black).

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 3 . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 2 . W . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . a , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Pros don't play like this but quite a few amateurs might so it's good to be clear how to take advantage.

For real-game examples, here is the OGS game (with embedded comments which due to bug in nova OGS all show up one move too early!) where I learnt the hard way about the big knight being a good answer to white reinforcing the side group:
And another with the normal continuation that ez4u showed in which white's cramped 2 space extension later dies as he overplayed and invaded the extension below before reinforcing the 2 space group.

Thankyou very much ez4u and Uberdude for the detailed explanations, Very handy.
Getting closer and closer to a solid 6k rank, now!