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Lost points from mid to end game
http://www.lifein19x19.com/viewtopic.php?f=4&t=18729
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Author:  ccb138 [ Wed May 11, 2022 8:23 am ]
Post subject:  Lost points from mid to end game

Today I played a game against a 9k AI on OGS and analysis on AI Sensei seggests that by move 139, I had a lead of around 14 points, but it got slowly chipped away and I lost by 8.5 points. I was wondering if there were any general themes or common errors that others notice that are contributing factors I could work on. Any suggestions are much appreciated!!

I played black.

Attachments:
43655586-232-doge_bot_4-ChrisBecker.sgf [2.56 KiB]
Downloaded 286 times

Author:  Joaz Banbeck [ Thu May 12, 2022 8:54 am ]
Post subject:  Re: Lost points from mid to end game

If you present it like this, it is easier for people to review.
Note how the sfg tag is used here.


Author:  Joaz Banbeck [ Thu May 12, 2022 9:31 am ]
Post subject:  Re: Lost points from mid to end game

The first eight moves are reasonable, but your game turns inward on move 9.
This is a bad exchange for you.

Click Here To Show Diagram Code
[go]$$B Moves 9 to 10
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . X . . . . . |
$$ | . . . B . . . . . . . . . . . O . . . |
$$ | . . 9 . . . . . . . . . . . . . . . . |
$$ | . . O 0 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


The circled stone is a high stone. It is not territorial. Trying to make it part of a territorial group this early is a misuse of its potential.

If you are really concerned about his C12 stone, this is more consistent and thematic:

Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . X . . . . . |
$$ | . . . B . . . . . . . . . . . O . . . |
$$ | . . . . 9 . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


However, that is still giving the C12 stone more credit than it deserves.

If you want to limit white's expansion on the left side, do it on a large scale, like this:


Click Here To Show Diagram Code
[go]$$Bc Play a stone in the biggest open space on a side.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . X . . . . . |
$$ | . . . B . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . 9 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Or, my favorite would be to ignore the left side completely, and capitalize on his failure to finish the joseki over on the right:


Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . X . . . . . |
$$ | . . . B . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 9 . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In summary:

1) Think large scale. Look at the whole board.

2) Look at https://senseis.xmp.net/?HighAndLowMoves

Author:  ccb138 [ Thu May 12, 2022 3:36 pm ]
Post subject:  Re: Lost points from mid to end game

Thank you very much for your time and help!

Author:  jlt [ Thu May 12, 2022 10:47 pm ]
Post subject:  Re: Lost points from mid to end game

The main reason why you lost points at the end of the game is that, at move 161 and onwards, you missed H10 which destroys a lot of white territory, and made a lot of small moves instead. But I'd say that's not the main reason why you lost the game. Generally you were too defensive. See for instance Joaz Banbeck's last diagram: watch your opponent's groups, and if you can find a weak group, try to attack it.

Other remarks:

  • Move 23 is better at S7. If White responds with R8 then Black keeps sente while not giving White too much strength.
  • Move 27 is big but passive. How about putting pressure on the weak group D12 or on the stone Q14? D4 is not very strong either, a pincer at H3 may be interesting.
  • Move 47: White didn't defend the corner, don't you want to continue attacking it?
  • Move 55: are you afraid of the cut? Suppose White cuts, can you find a way to capture the cutting stones?
  • Move 103: you are not defending many points. There are bigger points elsewhere.
  • Move 129: save one stone?? There are bigger points elsewhere. For instance R18 (then White S18, Black Q18, White S19) reduces the corner in sente.

Author:  ccb138 [ Sun May 15, 2022 1:06 pm ]
Post subject:  Re: Lost points from mid to end game

Thank you for pointing those out - they were helpful. I think you're right - I get scared and try to defend everything =).

Author:  Joaz Banbeck [ Sun May 15, 2022 1:25 pm ]
Post subject:  Re: Lost points from mid to end game

Also, the invasion at 31 is suicidal. It forces white to split your groups so that he can attack both. I'm amazed that your left side group did not die.

I would have slid under with B4.

Or, if I were really determined to invade, I would have delayed the invasion by attacking his left side group with something like F10. Then, when the group has a clear path to go eastward or has enough territory for eyes, I would invade.

Author:  Ian Butler [ Mon May 16, 2022 12:40 pm ]
Post subject:  Re: Lost points from mid to end game

One thing that pops up when I watch this game is this: small knights can be cut :) I notice that black has a tendency to play a small knight and white almost always immediately cuts it off.

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