# BQM79

White's turn. Yose, some stones in the center are not shown. Which move is bigger?

Alex Weldon: Given than this has been unanswered forever, I might as well take a stab at it, even though I'm no endgame whiz.

Ignoring the center, since we don't know what's there, answering at *a* gives White 9 points, assuming that we're counting the corner points as fixed, and that the situation in the center allows Black to reduce at *c* and *d* in sente at some point. Black has 3 (again, assuming his territory down the side is fixed). The total is 6 for White.

After , and will be sente. will probably be answered at . Later, there are a number of gote plays for both players. It's hard to know exactly what White will get, but probably at least some of the circled points, so let's say 2 or 3. Since the total in the previous diagram is 6 for White, and here White gets 6 on the left (3 territory + 3 prisoners) and Black gets nothing, *b* is points-wise better than *a* by however much White gets on the top - a few points, anyway.

However, White ends in gote this way, and in sente by answering at *a*. Therefore, to choose between these two moves requires one to estimate the value of sente. If there are moves bigger than two or three points elsewhere, *a* is better.

Imagist: A generalization of this case is at mutual damage.

Bill: As is often the case, there is not enough information to give a definitive answer.

Assuming the stones are secure, - gains 4 1/2 points.

The other play depends upon the security of the stones. If they are secure, then Black can jump to *b*. It is not easy to calculate how much the jump gains, but I think that it gains a little less than 4 1/2 points. (Normally such a jump is larger, but White's stones in the corner reduce Black's potential there.)

But if the stones are not secure, Black can probably play at *c* with sente, threatening to play at, say, *d*, using their weakness to march into the corner. In that case White should reply to *Bc* at *e*, and *Bc* is a 5 point sente.