Endgame Problem 25 / Solution

White wins by one  

Bill: A fine point: is better technique than playing the sente at first, because it gives White the chance to make a mistake [with at , letting Black jigo with the hane at the top].

Only jigo  

Discussion

Robert Pauli: (pointing at the diagram on the main page)
Locally best play isn't globally best play, as everyone will find out sooner or later.

I like these miai values (even if I'm still struggling with them), however, would they help White in any way ??

Bill: Gee, maybe I am missing something, but the best local play seems like the best global play to me. (OIC. It depends on what you mean by best play. I think you mean optimal play. I had orthodox play in mind. The normally best local play differs from the best global play at or below temperature 1. They are the same above that.)

Robert Pauli:
Hmm, I'm ahead of the solution in DGoZ 6/03, but . . .
(showing him both diagrams above and pointing at the second)
Locally best for the lower part, but missing the win.

Are you using some kind of mathematical never-ever-draw rules, Bill, or what am now I missing? ;-)
So, how do miai values direct White to choose the "inferior" move?

Bill: Here is what I mean:

Normal local play  

After , White has - with sente, and Black has - with sente. This is 2 points better than the result above, starting with . With rare exceptions, W should play unless the remaining plays are very small.

( - is sente because of possible later threats against Black's group. But even if it is a 2 2/3 point gote instead of a 3 point sente, is still the normal local play.)

was my first thought, and then I wondered why this was a problem. ;-)