Life In 19x19

For me this is a new way of thinking. Before I would not have thrown in the Q18,R18,S18 stones since they cannot live with eyes, unless I could read out the kill

Thanks!

Tapani wrote:P19 tesuji ... you mean "clamping" the P18 stone before chosing side to cut? Does that work?
Or do you mean start the capture race with P19 in case both groups have three libs? Thought that could lead to ko (after black O19).

Not to steal Uberdude's thunder, but I think he means your hane at P19. We don't usually think of moves that are obvious to us as tesuji.

Tapani wrote:

UberDude wrote: Tapani, Good job on spotting black's weaknesses with r15 and all those cuts. What would you do if black connected at s16 for move 77? Also p19 is a good tesuji to know (my 2d opponent in a recent tournament missed it!) and it would be the only move to win the race if your corner stones only had 3 liberties (e.g. no white stone at s18), but with the extra liberties your inside stones have you can also play m18 and win the capturing race, and then black can't even cut off the k16 stones like he did in the game as some compensation for the clump dying.

For the S16 connection (which is what I expected black to play), I would have played S13 and taken the two stones and the right side. Perhaps my M16 group ends up in trouble, but in the worst case it is a trade.

I thought you might. But that would be a mistake. If black defends at s16 because he spots the cut weaknesses, the key thing to realise is that white has already gained from that exchange. You have created the option to take the 2 stones, but you don't need to do it now because that white group is already strong so it's just a big endgame move now. Better would be to get the group on the top out to safety, and start that with the m18 descent in sente. You don't want to do that BEFORE s14 because it forces black fix the o18 weakness, but once black defends s16 (scared of the o18 weakness if he can read that far) now is the perfect time to play m18. You can have your cake and eat it too!

As Bill said I mean the p19 you played in the game.

Tapani wrote:Or do you mean start the capture race with P19 in case both groups have three libs? Thought that could lead to ko (after black O19).

Yes. But it's not a ko, you atari from n19 and connect and die.

Uberdude wrote: You have created the option to take the 2 stones, but you don't need to do it now because that white group is already strong so it's just a big endgame move now.

Aha! I understand! The fact that it does not influence life/death status of any groups makes the move of lower priority.

This also connects with something I have heard Dwyrin say on his stream: sometimes he says that a move is "only points" or "only territory". Maybe this is what he means!

However delaying the capture of the two stones makes R12 a large point for black too (it saves the stones, makes a few points territory, and kills the cutting stone).

Uberdude wrote: Yes. But it's not a ko, you atari from n19 and connect and die.

Ah, I see. No need to fight the capture of one stone when we can kill the bigger half

Now I wonder if the initial cut at S14 was really needed, I did it to gain the third sente move (S18) in the corner. Perhaps the black stones were killable even without it?

Thanks a lot!