Cash game, Black owns the cube.

White to play 6-2.

This isn’t a terribly tough problem but it does contain an interesting point.

First, let’s note that all the reasonable plays start with 23/17. Abandoning the checker on the 23-point by playing 17/11 can’t be right in any universe I know about, so let’s play 23/17, then look for the best two. Three candidates quickly appear:

a) 17/15

b) 10/8

c) 8/6

Play (a), 17/15, we have to discard pretty quickly, since it leaves two blots and a triple shot (5s, 3s, and 1s all hit, while 3-2, 3-1, and 1-1 are double-hits). It’s true that none of these hits are immediately decisive. But that’s also true of the blots that White can leave in the other variations. In addition, the anchor on the 17-point is attacking both Black blots, which is a strong argument for keeping the point.

If White doesn’t play 17/15, then he has to break one of his outfield points and leave a shot. The obvious break is 10/8, because we have learned from experience that breaking a prime from the back is usually better. But this isn’t really a prime, and after White breaks a point, he should be able to play for a couple of turns before he has to dismantle another point.

The right play is actually 8/6, for a couple of reasons. The first reason is just our old friend duplication. After 8/6, Black need fours to hit and fours to button up both outfield blots, so he doesn’t have many good numbers at his disposal. The second and less important reason is that by breaking the 8-point but retaining the 10-point, White gets some extra shots if Black rolls 4-1, 4-2, or 3-1 and decides to hit. This idea is often a reason for breaking an interior point rather than the back point. Breaking the rear point is often right when White is bearing home and the rear point is really the rear point; it’s sometimes not right when the whole board is still in play and White need to keep his army from being disconnected.