Problem of the Week #60: Solution


Cash game, center cube.




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


Note: All ‘cash game’ problems assume the Jacoby Rule is in effect. That is, you can’t win a gammon unless the cube has been turned.


Problem 60 shows a pretty interesting middle game position. Both sides have an anchor, and some points scattered around. Black, however, is on roll and shooting at a bunch of blots. He has a total of 27 hits: all sixes, all fives, 4-3, 4-1. 3-2, and 3-3. That’s a lot of hits, so he’s naturally thinking about doubling, and White is probably worrying whether or not he’ll have a take if Black ships the cube.

I like to call these positions “Action Doubles”, because there’s a big equity swing when Black hits one of his shots. If he hits, White could be forced into some sort of back game/holding game; if he misses, White’s blots all become builders and he’s in decent shape.

Let’s start by evaluating the double according to Sylvester’s Law: we’ll look at the position, the race, and the threats.

(1) Positional advantage. Both sides have an anchor, although White’s anchor is superior. Black’s extra inner-board point is offset by the fact that it’s behind White’s anchor. Black has the outline of a blockade, while White is hampered by the stack on his 6-point. Slight edge to Black.

(2) The race. Black leads by 12 pips, 142 to 154. Given the amount of contact in the position, a 12-pip lead isn’t a big deal at this stage.

(3) Threats. Black is shooting at three blots and most of his rolls hit. Big edge to Black.

Black has a big advantage in threats and small advantages in position and the race, so the double looks pretty solid. Now let’s consider the take.

In action doubles, most of the take decision hinges on whether the defender has an anchor or not. If he does, it’s usually a take; if not, it’s likely to be a pass. Here White has a very good anchor, while in addition Black’s board isn’t that strong. These two factors suggest it’s a take, and in fact that’s right. Passing here is a big blunder, costing White almost 0.3 points/game. The most likely sequence on the next roll is that Black hits one blot and White then reenters, after which most of White’s troubles have subsided. He’s down in the race, but he’s holding a great anchor and maybe one other point as well, while Black still has to bring his men around the board.

Don’t be afraid to take just because your opponent is likely to hit a blot. If you have an anchor, your checkers are all in play, and the game rates to go on for awhile, it’s not likely your opponent is a 3-1 favorite yet. Take the cube and make him win the game.


Solution – Black should double, and White should take.