Hi all,
I recently played a 13x13 game where my opponent played some weird tesuji against my 3-4 corner that I didn’t know how to answer. I am talking about the sequence that starts at move 6. My reaction was to keep white separated while trying to keep a foothold in the corner but I think the result was good for white.
Anyone can think of a better play?
https://online-go.com/api/v1/games/9328963/sgf
Link to the actual game:
It’s quite simple - corners are not good because they have a spike, but because they give you easy stability with decent points. (Don’t believe people who say, that corners are good because it’s easy to enclose territory in corners - total bs). If you look at your corner after move ~14 it’s clear that your group is nor stable nor has any reasonable territory.
Having said that I hope it’s obvious to you that the mistake was at move 7 - you over invested in treating the corner as territory. If you tried to stabilise your group instead what would you chose? I left you some variants in the review https://online-go.com/review/257199
At move 21 you could have played L8. After that, there would be no more problem with your corner ;-).
Definitely not a tesuji 
It’s not that obvious to me, and I wouldn’t label move 7 as THE mistake. Some later moves are much worse. I posted a review.
Agree.
Agree that it was not the only mistake, but definitely the first one. Also it highlights the preconception of trying to defend corners territory at all costs which in principle lead to the bad result. I’ve discussed other mistakes in the review, but the lesson that comes from this corner is not about a single misread that could have saved the day (L8), but rather slight change of perspective on the role of corners.
I.e. “you want this corner so bad that you play 6th move on 2nd line? Go ahead, If you want to help me build a 3rd line wall outside, I’m happy to share the corner with you” - this should be the primary instinct.