Simba wrote:
Do you feel that Lee wouldn't have played S13 if he'd known it to be (temporarily) gote? That move is huge even if gote and has potential life and death applications for both groups.
Yes, it's big (maybe there is even a chance those 3 captured white stones make a dead shape?). I can only speculate how seriously Lee thought about a white teunuki, it would be interesting to hear his comments on it.
Simba wrote:
I feel personally that R4 instead of Q5 would be more sensible, since then black would make some territory in the corner rather than white, but it's possible I'm just thinking too naively with this.
q5 makes some sense following s13 in that it aims to separate the big white wall group from the corner and ask where its eyes are (as s13 threatens q15 which takes away those eyes and possibly kills the whole thing). But the problem was white settled in the corner
in sente and then came back to answer s13 at the top right to make eyes. But yes r4 to make corner points was probably better as most commentaries say. Given that white answered q5 at q6 (rather than r4) I think p6 at r4 to get the corner (and leave white with more cuts that direct r4) would have been better. Commentary also said p6 was bad (the losing move says An Younggil) and should block the corner, but the problem is white has the fine tesuji at s5 to both defend the r6 cut and threaten to kill the corner with s3 in the variation following move 128 r4 r3 p6 p2 s5 s3 so can then return to the top right at t14 or whatever. Still should be better than the game though.
Simba wrote:
What do you think of black's R17 attachment? It's 'bad' in this joseki, but do you think maybe the pros are just missing something by claiming this? It'd be really cool if some new joseki were discovered with AlphaGo's help.
Locally speaking I still think it is bad, but the problem is it is not as bad for white as white getting the j16 pincer is for black. Younggil says move 15 q13 (the standard punishment) was questionable. So I guess black should have played j16 himself and endured the suffering of white r14? In fact I think this opening shows that Lee's unusual move 7 at r8 (presumably attempting to make a fuseki AlphaGo hadn't seen in the training) was bad and mini-Chinese or something normal would have been better (r8 also ended up inefficient to my eyes following the pushes, and then the brialliant r10 much later embarassed it). Kasparov's comment about humans playing suboptimal moves attempting to exploit or trick AIs is spookily prescient here: