Life In 19x19

Posted: **Tue Dec 24, 2019 1:28 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X B | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . . | $$ | . . . . . . . . . . . . X O O . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Tue Dec 24, 2019 3:58 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . W X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . . | $$ | . . . . . . . . . . . . X O O . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Block from this direction, rather than from R8, to reduce forcing moves from the outside.
Block at P8 instead of P10 or P7 to make forcing stones around O10 or O7 worse (see below).

Click Here To Show Diagram Code: [go]$$c Ex. 1. Even with most passive response, Black forcing stones have two liberties each. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . 1 2 X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . W X . . . | $$ | . . . . . . . . . . . . . 3 4 X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . . | $$ | . . . . . . . . . . . . X O O . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

In the above example, White could also try to net the stones, as well as other options.

Click Here To Show Diagram Code: [go]$$c Ex. 2. If White P10, Black forcing stones can have more liberties or better play with each other. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . W X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . 1 2 X . . . | $$ | . . . . . . . . . . . . 3 . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . . | $$ | . . . . . . . . . . . . X O O . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Comparing these two examples, both achieve the same immediate goal, but have different future outcomes. If you have a choice between moves that achieve the same immediate goal(s) and choose the one that removes one or two additional liberties, a few of these choices can suddenly add up to big changes, such as in fighting variations. Speaking larger, this can reduce opponent's options and increase yours; and is how games are won and winning positions are solidified. Most strong players enjoy the satisfaction of playing these kinds of moves.

Posted: **Tue Dec 24, 2019 6:53 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . B | $$ | . . . . . . . . . . . . X O O . O O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Tue Dec 24, 2019 9:01 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X . X | $$ | . . . . . . . . . . . . X O O . O O W | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Tue Dec 24, 2019 9:05 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . . . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X B X | $$ | . . . . . . . . . . . . X O O . O O O | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Tue Dec 24, 2019 9:07 pm**

Click Here To Show Diagram Code: [go]$$c B:3 W:0 $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O O X . . | $$ | . . . , X X . . . , . . . . . X O . . | $$ | . . O O X . . O . . . . . . O X O . . | $$ | . . X X . . . . . . . . . . O X . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . O O O X X O | $$ | . . . . . . . . . . W . . O X X . X X | $$ | . . . X . . O . O , . . X X O X X X . | $$ | . . . . . X X . . . . X . X O O X X X | $$ | . . . . . . . . . . . . X O O . O O O | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Posted: **Tue Dec 24, 2019 10:34 pm**

I resign. Thank you for the game.

Posted: **Tue Dec 24, 2019 10:46 pm**

Thank you for the game, and have a Happy New Year!

Posted: **Sun Dec 29, 2019 4:42 pm**

I hope it's not too rude to post my interpretation of an AI review on this game, because I'm doing it!

First, let me congratulate both players on a VERY well played game. On my first pass through of this game with my low-playouts slightly old LZ version, there was about as much +% change as -% change from move to move. That means that you guys played at a level very close to AI's 'instinct' level

Here's a picture of the evaluation graph after more playouts:
https://imgur.com/a/tfs9zuc

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Black took a slight lead in the opening, apparently. It seems to me that AI doesn't particularly like the probe that fevebod152 played in the lower right. After that, it seems like it wanted white to take more influential variations in the top left, to harmonize with white's very centrally-oriented bottom side.

One blue move that surprised me:

Click Here To Show Diagram Code: [go]$$c LZ's suggestion $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X . . . . . . . . | $$ | . . . O O X . . . . . X . X . X . . . | $$ | . . . . . . . O . . W O . . . . . . . | $$ | . . O . . X . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . O . X . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . O O X X . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . O . O , . . . . . X . X . | $$ | . . . . . X X . . . . . O . O O X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Both the players and I thought that W couldn't possibly afford to take gote in this totally unimportant area, and were impressed by fevebod's grasp at sente. LZ thought the taking this good shape was worth the full move - rating it very slightly better than fevebod's move. The idea appears to be taking the left side in security, and claiming the middle will end up as an investment in dame. Here's a sample variation I picked:

Click Here To Show Diagram Code: [go]$$Wc Fair for both, apparently. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X . . . . . . . . | $$ | . . . O O X . . . . . X . X . X . . . | $$ | . . . . . . . O . . 1 O . . . . . . . | $$ | . . O . . X . . . . . . . . . . . . . | $$ | . . . . . . . O . . . . . . . . . . . | $$ | . . . O . X . . . . . . . . . . . . . | $$ | . . . . . . 2 . . . . . . . . . . . . | $$ | . . . 7 . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . 3 5 . . . . . . . . . . O O X X . | $$ | . . 4 . . . . . . . . . . . . X O . . | $$ | . . . X . 6 O . O , . . . . . X . X . | $$ | . . . . . X X . . . . . O . O O X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

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The drop in black's winrate near the middle was well explained by fevebod in his post, suspecting a poor move order. He was completely correct. Also, rlaalswo made a second mistake later in the variation, on one of seemingly forced moves. I show an easy-to-evaluate variation suggested by LZ:

Click Here To Show Diagram Code: [go]$$c Better than connecting the stone in atari $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . . O X . X . X . . . | $$ | . . . O X 2 3 O . . . O . . . . . . . | $$ | . . O . O X . . . . . . . . . . . . . | $$ | . . . X O 1 . O . . . . . . . . . . . | $$ | . . . O X X . . . . . . . . . . . . . | $$ | . . . 4 . . O . . . . . . . . . . . . | $$ | . . . , 5 . . . . , . . . . . , . . . | $$ | . . 6 . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . O O X X . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . O . O , . . . . . X . X . | $$ | . . . . . X X . . . . . O . O O X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Black can now capture - white will answer, since black's ignoring any ko threat would be sente. Compared to the game, we have the same shape but for the ko aji of disconnection and the attachment to white's stone. Black will continue with a wedge at H14, which is clearly more powerful than the move black played in game at K16.

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Click Here To Show Diagram Code: [go]$$c Remember me complaining about this move? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X . . . | $$ | . . . O X X . O . . . O . . . . . . . | $$ | . . O O O X . . W . . . . . . . . . . | $$ | . . . X O X . O . . . . . . . . . . . | $$ | . . . O X X . . . . . . . . . . . . . | $$ | . . . O . . O . . . . . . . . . . . . | $$ | . . . , X . . . . , . . . . . , . . . | $$ | . . O . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . O O X X . | $$ | . . . . . . . . . . . . . . . X O . . | $$ | . . . X . . O . O , . . . . . X . X . | $$ | . . . . . X X . . . . . O . O O X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I was horribly wrong about the move that fevebod played and I complained about - LZ says it's the only move and every other move loses >5%!! I took about an hour to convince myself of this, and to be honest don't have the energy to test my communication skills by relaying my new understanding of the shape in text. I do recommend studying this move in particular by yourself, though - I learned something tangible. If you wrongly agreed with me before, you'd do yourself a favor to put the position on a real board and do some deep reading until you're in fevebod's camp.

My criticism of rlaalswo's deep invasion was not so clearly wrong, but just slightly silly - both moves are ~71% winrate for white. When later I asked him whether he considered the cut, I was more curious about his decision making process than suggesting it as a good move. His verification that the cut was inaccurate was correct.
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Black hits his final peak winrate when he cuts. My AI was misreading this continuously - on 1-5k playouts it made a mistake every three moves or so. Analyzing became very tedious, and my conclusion may be inaccurate. That said, I suspect that with perfect play every complicated variation goes up in flames for black without hope of compensation. There doesn't seem to be a way to avoid a complicated position here, so this 62.5% position is just 100% winning for white - there's not even a way to find a 2 point loss as a compromise.
So the downward trend that black fell through after that? That same thing would have happened if this was an AI v. AI game, though perhaps it would have been a slightly shallower slope.

There's still something I want to show off, a tesuji that I missed, my AI initially missed, and that the players might not have given due consideration.

Click Here To Show Diagram Code: [go]$$c Can you find the tesuji for black? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O . . . . | $$ | . . . , X X . . . , . . . . . X . . . | $$ | . . O O X . . O . . . . . . O . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X O O . | $$ | . . . . . . . . . . . . . . O O X X O | $$ | . . . . . . . . . . . . . W . X . X . | $$ | . . . X . . O . O , . . . X . X X X . | $$ | . . . . . X X . . . . . O X O O X . . | $$ | . . . . . . . . . . . . X O O . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$c Tesuji! $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . X X X X O . . . . . . . . . . . . | $$ | . O O X O X . O . . X X . . . . . . . | $$ | . . . O O X . . . X O X . X . X X X . | $$ | . . . O X X . O . . . O . . . O X O . | $$ | . . O O O X . . O . . . . X . . O . . | $$ | . . . X O X . O . . . X X . X O . . . | $$ | . . . O X X . . . . O . O X X O . . . | $$ | . . . O . . O . . . . . O O O . . . . | $$ | . . . , X X . . . , . . . . . X . . . | $$ | . . O O X . . O . . . . . . O . . . . | $$ | . . X X . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . B . X O O . | $$ | . . . . . . . . . . . . . . O O X X O | $$ | . . . . . . . . . . . . . O . X . X . | $$ | . . . X . . O . O , . . . X . X X X . | $$ | . . . . . X X . . . . . O X O O X . . | $$ | . . . . . . . . . . . . X O O . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

This is a tesuji that all low/mid-dan players have seen and no low/mid-dan players have played

The point is that you want to help the cutting stone. Your natural instinct is the move rlaalswo played - extending to gain strength towards your opponent's weakness. But there's also some center aji that felt unexploited. Whenever you want to extend a cutting stone to side A, but miss out on the exploitation of aji to side B, you should consider this tesuji of jumping to side B. Your opponent dearly wants to cut you at P7, but if they do, then they're just giving you that extension that you wanted to side A, and defining their shape with an aggressive exchange on side B in the process. This doesn't actually win the game for rlaalswo, but it does make things more complicated to my eye (and to my AI).

The AI's top suggestion for white here? O6.

I would have loved to see this fight in a real game!

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So overall, this was a fantastic game, with the only clear mistakes being the pair of minor move order mistakes by rlaalswo around move 50. I would like to forcefully upgrade fevobod152 to high-dan, if not already secretly a professional. That was simply a flawless game by white, and near flawless by black.

Life In 19x19

#267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152

Re: #267 rlaalswo v. fevobod152