Charles Matthews: Can't agree with that, Bill. seems a perfectly ordinary idea here. (Later: database confirms that this is one of two major ideas in pro play, the other being the immediate wedge on Black's side.)
Velobici: and make the left side valuable to Black. At this point, Black has played every move on the fourth line (relative to the bottom). Black is clearly headed toward a moyo game. makes and much less valuable and is a five line extension from . This is a double value move.
Bill: I'll go along with that, Charles. Quelching Black's potential on the side makes a good play.
Bill: Compare this diagram with the game. Black's bottom right corner is weaker than his bottom left in the game. Again, White should play further away from Black's strength. has better development potential than in the game.
Charles This point is hard for me to understand. There is not enough database evidence here.
Charles But certainly in the analogous position the pros all head for here. So does having a black stone at the circled point change everything?
Velobici Indeed. Black has three moves on the fourth line vis a vis the bottom edge, undercutting both corners with is very good for White.
Bill: The Black stone at is certainly a factor I should have mentioned. White does want to approach Black's framework.
Bill: In fact the first place I saw the 9-3 wedge was in this position. The stone was key to playing closer to the right.
Bill: is White's first really questionable play. Since is cramped, there is something to be said for viewing lightly and playing tenuki to make a framework on the top side with a play at one of the b points. Locally, White should jump to a.
Charles I agree here: is not the best idea.
Bill: - are all questionable. Besides being premature, leaves a weakness behind. Better at c. strengthens White, to what end? is too close, but after - , not to play locally looks silly. is not only passive, it allows White to play , strengthening his top right corner and pushing Black towards White's strength on the left. Instead of , better the kakari at d.
Bill: To keep with the main theme, approaches strength. It makes look pretty good. If Black is going to jump out with this group, better jump to a.