BQM80

 

Black to play and capture the two white stones. The book tells me Black's best move is a, and White's best response is c, and I understand the rest of the sequence. But why is White's best move c? What happens if White plays b instead?

(note: Thanks to everyone. Misread the book. Black plays at b not a ...)

 

unkx80: Was there a typo in the book? I think the solution should be this.

icepick: This is what is termed the Crosscut Tesuji, from TesujiTheBook. unkx80's solution is correct.

Possible Continuation  

unkx80: Consider playing at a instead.

Tricky  

This is a given variation that can be tricky for Black. As Dieter pointed out, is the correct follow up.

Dieter's move  

This is Dieter's proposed move (). It looks good - this way Black not only captures the two cutting stones, but also the marked stone and . - Andre Engels, after improvement/correction by Dieter

Another one.  

unkx80: While you are at it consider this one. Of course you would have known the correct solution already, but what if...?

Descent  

Andre Engels: Dieter's descent again resolves the problem. Charles It may do; but now White at a is a reading problem. Andre Engels: The solution seems to be that Black connects at b and wins the capturing race by one move. But this position is surely more complicated than the books usually show.

Descent again  

Bill: Shouldn't Black descend again with ? Then it's me ari me nashi. The above is one variation. If is at , is at .