Killing / saving a dragon

[tj86430]

Here's a game I recently played:



In the end the dragon died (I believe the game would have been close if it hadn't), but I'm curious to know what is the correct status if after 105 black doesn't tenuki?

Naturally other comments are also welcome.

[topazg]

It looks alive to me, but it's complicated. Find a few moves that you aren't sure about for Black 106 and I'll post what I think White can do about them.

I'd struggle to kill it, anyway

[tj86430]

After a closer look it seems to me that if both sides play correctly white will get a second eye around F9. If that is the case then my next question is: when was white's last chance to secure life?

[HermanHiddema]

White is alive, because there is an eye at F9. If white can respond to G7 with F8, to H10 with G9 and to F11 with F10, then F9 is an eye.

E2 provides the second eye (C1-D1, F1-E1, F4-E3)

So it dies because G7 becomes atari dues to black's move at G5.

[tj86430]

So it dies because G7 becomes atari dues to black's move at G5.

So white 133 should have secured life, and since it didn't, black 134 should have killed?

[HermanHiddema]

So it dies because G7 becomes atari dues to black's move at G5.

So white 133 should have secured life, and since it didn't, black 134 should have killed?

Yes. You can, of course, play the ko, but it is a real flower ko for black.