Cash game. Center cube. White on move.

(a) Should White double? If he doubles, should Black take or drop?

(b) Should White double? If he doubles, should Black take or drop?

These two positions show a couple of very typical middle game doubles. In each case we’re six to eight moves into the game, one side has finally grabbed a noticeable advantage, and now they’re thinking about turning the cube. Double? Take? What’s right?

Let’s start with the doubling question. The best general guide to early/middle game doubles of this sort came years ago from Joe Sylvester. (Joe was one of the titans of backgammon in the 1980s and 1990s, and he won the first World Cup in 1988. Today he’s somewhat inactive.) Joe recommended looking at three features of the position: the race, the structure, and threats. His rule was the following: if you have an edge in at least two of these three, then you have a double.

With this idea in mind, how’s White doing in Position (a)?

> White leads in the race, 133 to 149, a 16-pip lead.

> White has a better structure, with a 4-point block, his 4, 5, and 6-points already made, and good distribution. Black lacks his 4-point and 5-point and has a big stack on his 6-point.

> White has plenty of immediate threats. Twos hit the blot in Black’s board, 6-1, 6-3, and 3-1 make a 5-point prime, and 6-4 points on the 2-point. White’s edge is threatening to get much bigger next turn.

With an edge in every department, Sylvester’s rule suggests White should have a strong double in Position (a), and in fact he does.

Now let’s look at Position (b).

> White leads in the race, 134 to 162, a 28-pip lead.

> White has a better structure, with four points made in front of Black’s anchor. In addition, Black has three men back on his 23-point, which is weak. Black also has no inner board yet, which is also weak. Here the issue is not so much that White is strong, but that Black’s pretty weak.

> White has no particular threats. True, 6-1 makes his 5-point, and a few numbers will run his back checker into the outfield. But that’s more the sort of background threat noise that’s present in every position.

Here, we can say that White has an edge in two out of the three criteria. Again, he has a solid double.

Now, what about the take/drop question? Here I’ve got my own rule. I ask myself three quick questions. If the answer to the first and third questions is ‘yes’, and the answer to the second question is ‘no’ I’m pretty sure I’ve got a take. If not, then I’ll look at the position more closely. My questions are:

> Do I have an anchor?

> Does my opponent have a 5-prime?

> Is there still contact on both sides of the board?

Take a look at Problem 1 and Problem 2. In both cases Black has an anchor, in both cases White hasn’t yet built a 5-prime, and in both cases we still have contact on the other side. With all these conditions in place, it’s hard (although not impossible) for Black to be a 3-to-1 underdog in the game. In both positions, Black’s best guess should be that he probably has a take. And in fact, rollouts show that’s the correct action.