Conundrums: Empty triangle and territorial reduction
I had a good game (SGF link) against goisart (19k) this evening but I still lost by 16.5 moku. My lower moyo collapsed when I responded to W-O3 with B-O4. In hindsight, I think B-N4 might have been better even though it created an empty triangle.
My opening moves were poorly coordinated. I played B-G17 (Move 21) in gote and so White was able to extend with W-D10 (Move 22). I think Move 21 was wholly unnecessary and Move 22 was obviously big for White. Had Black taken D10, it might have helped neutralize the influence of White's wall.
White also limited my shimari at B-R5 (Move 31) with his extension to W-K3 (Move 32). After B-M3 (Move 33) I tried to reduce White's moyo with B-H4 but this probably wasn't the right move. I couldn't see an exit path that was reinforcible. Maybe there was a better way? Maybe B-J5 would have worked instead?
Perhaps I should have launched my invasion at C7 at this point but, judging from White's strength, I expected to live small and only give White more central influence.
I also wonder whether it was wise not to have played my 3rd move at R9 to create a Chinese opening.