Joaz Banbeck wrote:Ok, you guys have completely trashed my first 30 moves. Thanks. What about the rest of the game?
The moves starting with B45 seem really strange. Just connect against the peep? If White leaves the situation alone after that, you have a target to attack. Otherwise you have sente. After the game sequence, at move 60 White has influence up the left-hand side, while Black still has bad shape in the corner.
Some comments which will hopefully help improve your game, plus a few comments for W as well. Your play is already good and solid, so most of these comments are only pointing out subtle problems, but at the dan level these become important.
I see nothing wrong with the B extension to P4 (move 5). The hane which everyone else prefers is certainly also good, possibly even better, but not enough to worry about. In any case, the W invasion seems too early, and B is off to a great start.
The exchange O4 N3 (move 7) however is bad, partly because it is pushing from behind, partly because it lessens the severity of the following keima. Without that exchange, the keima threatens a push-and-clamp which would be more painful to W than any continuation B has after the actual game sequence. If you like tewari analysis, imagine that B could replace the two stones in the game at O4 and M5 with a single stone at N5 plus a free move elsewhere on the board (assuming W plays the honte response at N3 to prevent the push-and clamp).
The W play at Q8, designed to prevent a good B extension from the wall, is a reasonable strategy, but the actual move is too close. W could better achieve his objective by playing one space farther away. B would still probably want to pincer, as extending from the wall would be over-concentrated, but then W would be able to defend much more comfortably. If W moved this stone two spaces farther away, then B might have a hard time deciding whether to pincer or to extend from the wall, a good indication that this is likely the ideal approach distance.
W compounds the problem next move by approaching even closer to the wall. Surely you realized that the last two W moves were bad, and hence B now has the advantage? When your opponent gets into trouble like this, do not let him off the hook! The B extension to R15 is nice and certainly preserves the lead, but why not attack more strongly? B has two good strategies: undercut the W base at R9 or cap at O8. Either way, you can look forward to a long and profitable attack. As MW might say, B has an opportunity here to dictate the flow of the game to his advantage.
In almost all corner positions, the hane-connect at S3 is a huge move. But surprisingly, in this position, I do not think it is very effective. It does not make or destroy eye space for either side, it is not needed to prevent a W connection, and it does not have a strong follow-up in either direction. Also, W would have a hard time playing first in this area, as any W move which helps one group hurts the other group.
Move 19 (O6) is too clever. Defending the cut directly at N5 is correct and makes the previous W move very bad. I imagine you saw that this defense worked (W cannot cut), but disliked giving W a useful peep. But since B later had to spend a full extra move defending N5, this was a false economy. If you look a little deeper, W has a serious liberty problem if B blocks directly at N5, likely requiring immediate defense. (B threatens P3 P2 O2 Q2 N2 and W cannot hane M2.)
Over the course of the next few moves, B played several weak moves and lost control of the game. By move 26, I think the position is roughly even.
At move 29, B needs to defend the cut, but it looks like he has a more active defense than the direct connection (which induces W to play a good extension). Surely part of the value of K6 was to threaten the clamp at K4? It looks like that clamp now prevents W from cutting.
Some moves are so obvious that they tend to be played by reflex. The B hane H8 (move 47) might be an example. I am not sure how much thought you put into this move, but if it was a reflex, pause to consider alternatives. Here I think the natural flow H8 G8 H9 F7 just helps W take care of his two weak stones on the left. F8 looks much better to me; if W responds around H9, B still has time to run out with the center group. If you really want to defend the center first, just jump to K10, without inducing W to strengthen his position. By move 66, something clearly went wrong for B, as now instead of two weak stones on the left, W has a large territory, while B has gained very little in compensation.
It looks like you already have a good appreciation for good shape moves. But when making a shape move, pay a little more attention, consider the likely continuation, and make sure your stones actually end up working efficiently. Move 89 (F12) looks like good shape, but when W plays hane at H14 and B feels compelled to respond at G13, it ends up misplaced. B could play H14 first to prevent this result, or F12 could be played at G11 (aiming at the freebie F10 if W does not respond). Or maybe the earlier hane at H13 was the problem, even though it looked like a nice shape move?
Consider the order of forcing moves, and avoid aji-keshi defensive moves if at all possible. When W played F2 (a delayed response to the B peep at E2), he threatened a large cut at D5. If B is going to defend, D5 looks like the correct move. Then W would have to worry about lots of aji like B7 or B8 or C8. B could also play B7 directly, since if W blocks and B draws back, the cut at D5 is protected. In the actual game, B pushed first at C6, destroying all this aji, and after the forced connection, W still had the large cut at D5.
The cut at C12 eventually won the game, when W responded by killing his own group. If W simply draws back to D11, B has nothing here. Of course it took several more W mistakes to actually kill the group.
Edit: I did not even look to see that B can push and cut at P3 after the W jump! This makes the B move at P4 even more playable. However, I amend the exchange O4-N3 from marginally bad to terrible! The game is over if you push and cut.
Thanks.
I can't believe how much I missed.