Life In 19x19

This is a game I played last night. I am white (I deleted the name of the other player for privacy reasons). I would appreciate a little bit of analysis from stronger players on direction of play and "big vs. urgent moves". My opponent played some small moves in the beginning and gave me sente several times. How good are the choices I made when that happened?

I went over the game with LZ (there are some variations in the SFG or single moves where I didn't see something or made a mistake) and then I wrote a little about some specific moves; I would appreciate feedback on my heuristics/thought process.

The game’s pretty much over from move 83; I only had LZ do 400 playouts from here to the end. But I would welcome any comments or feedback; I know I made a lot of small mistakes (I was in byo-yomi).

Move 6 - LZ preferred 3-3 (which I’m not confident doing so early), or approaching the bottom right corner from either side. What is wrong with splitting?

Move 20 - I played D10 because I thought it helped my group and it worked nicely with the 4-4 stone in the upper left. I don’t think LZ gave it any thought.

Move 22 - Even though it isn’t the biggest side of the board, I played here because I thought that the R14 approach would be very nice for black, especially if I back off. A side of the board that is desirable for both players. Playing elsewhere (F17 enclosure, i.e.) didn’t seem very good, as in the variation. Playing R14 myself seemed too small and left the large, unplayed top open. Is this a case of “white is so far ahead that there is practically no ‘bad’ move?”

Move 28 - I really wanted to play F15, as in the variation, but I thought that if black turns I have to play at E15 anyway, so it isn’t very efficient. I also thought that this variation is too easy for black to live and then harass the white group on the left side (IF - big if - white tenukis at move 34, which I may have done, even though C16 bamboo joint seems obvious in hindsight).

I really hated playing both D12 and E14; such cramped shape. I have learned why it is better to kosumi at C15 rather than armpit hit at C14…

Move 36 - I thought it was pretty natural to take an enclosure after I already had an extension; it also makes the top a bit smaller.

Move 40 - big mistake. I was lucky I could go back and fix it.

Move 44 - big mistake. I thought it was “sente” in the sense that if black didn’t respond white could take some of the corner away… I was lucky black responded; I should have just descended at B14 or haned at B13.

Move 54 - sort of a waste of a move. Why should I care if black lives small on the top? I should have either extended at H16 or played F11 (as LZ is screaming at white to do — which I did play later)

Move 68 - LZ really doesn’t like this move. I guess because F11 is more urgent? I was lucky that I got these two free moves.

Thank you!

For move 44, you could have killed black in the corner with B15. The best black can do is form the L+1, but since you get the next move you can kill it: https://senseis.xmp.net/?L1Group

About move 6: Rin Kaiho (and many other professionals) have played it, so it can't be a bad move.



Generally speaking, LeelaZero likes territory and dislikes 5-space extensions, so prefers to invade a corner/approach a corner/make a corner enclosure. That it doesn't consider some moves doesn't mean these moves are bad.

jonsa wrote:This is a game I played last night. I am white (I deleted the name of the other player for privacy reasons). I would appreciate a little bit of analysis from stronger players on direction of play and "big vs. urgent moves". My opponent played some small moves in the beginning and gave me sente several times. How good are the choices I made when that happened?

I went over the game with LZ (there are some variations in the SFG or single moves where I didn't see something or made a mistake) and then I wrote a little about some specific moves; I would appreciate feedback on my heuristics/thought process.

The game’s pretty much over from move 83; I only had LZ do 400 playouts from here to the end. But I would welcome any comments or feedback; I know I made a lot of small mistakes (I was in byo-yomi).

Move 6 - LZ preferred 3-3 (which I’m not confident doing so early), or approaching the bottom right corner from either side. What is wrong with splitting?

It's a single purpose move and not dynamic. What does it threaten?

Edit: With apologies to Rin Kaiho, Takagawa, and others, the bots are teaching us that these plays are smaller than we thought, especially at move 6. They really should be considered second tier opening moves.

Move 20 - I played D10 because I thought it helped my group and it worked nicely with the 4-4 stone in the upper left. I don’t think LZ gave it any thought.

White is quite strong in the bottom left corner and does not need an extension. OTOH, the K-03 stone is not strong. H-04 would work with it and be big in itself.

Move 22 - Even though it isn’t the biggest side of the board, I played here because I thought that the R14 approach would be very nice for black, especially if I back off. A side of the board that is desirable for both players. Playing elsewhere (F17 enclosure, i.e.) didn’t seem very good, as in the variation. Playing R14 myself seemed too small and left the large, unplayed top open. Is this a case of “white is so far ahead that there is practically no ‘bad’ move?”

It's not like your extension is bad. But it seems like LZ thinks it's a little too early to play it.

Move 36 - I thought it was pretty natural to take an enclosure after I already had an extension; it also makes the top a bit smaller.

I don't know what LZ recommends, but F-12 looks good to me. It works well with the center oriented plays White has already played. A move that should be on your radar.

Move 68 - LZ really doesn’t like this move. I guess because F11 is more urgent?

Yeah, F-12 and F-11 are both big.

If we look at the end position, we see 7 black groups, 3 of which die. That's a successful divide & conquer strategy if I ever saw one.

Biggest mistakes as identified by LZ: 40, 44, 64 but ... can we understand WHY you made these mistakes?

40: probably a misguidance by the strong heuristic "hane at the head of two". Higher level heuristic: play away from strength.
44: cutting of the wrong branch, difficult to know why you played here. Heuristic: cut weak groups from each other, don't cut strong groups, or even a weak group from a strong group.
64: possibly a consequence of not doing enough L&D; for someone who does, the move suggested by LZ comes naturally

So
1) apply high level heuristics, rather than visually triggering ones
2) cut weak groups
3) do more tsumego

Be well!

At move 20, I would have played H4 or K5 or maybe even M4.

You can't secure the left side even if you move first. So you are going to attack whatever he plays there. Double down, make your wall bigger in preparation for the eventual fight.

Thanks to all of you who took the time to look through my game.

BlindGroup wrote:For move 44, you could have killed black in the corner with B15. The best black can do is form the L+1, but since you get the next move you can kill it: https://senseis.xmp.net/?L1Group

Oh yes, you are quite right. Thanks for pointing me to this page.

jlt, thanks for the game -- I quite enjoyed going through it. (even though Rin Kaiho, who played the move I did, lost!)

Joaz, Bill, I quite agree with you both on Move 20 - H4. I thought about it, but I thought it was too slow. I was waiting for 'the right time', but it never came!

Bill Spight wrote:I don't know what LZ recommends, but F-12 looks good to me. It works well with the center oriented plays White has already played. A move that should be on your radar.

Okay, good to know. I thought that is was big, but I obviously underestimated how big it was.

Knotwilg wrote:40: probably a misguidance by the strong heuristic "hane at the head of two". Higher level heuristic: play away from strength.

Hmm, that's certainly possible. I don't remember exactly what I was thinking; now I realize that the top is much bigger than the corner here (in terms of what I would be "giving up"), and that black could (hypothetically) run along the second line on top and make eyes -- that's why I would descend to E18 here.

Joaz Banbeck wrote:You can't secure the left side even if you move first. So you are going to attack whatever he plays there. Double down, make your wall bigger in preparation for the eventual fight.

I think that is important for me to consider/remember; I felt, after move 20, that I had "claimed" the left side - which it really wasn't, with only a single move. I guess I, indirectly, tried to use a 'wall' to make territory.