Problem of the Week #4: March 29

Black has survived the first stage of an early 5-5 blitz and has established an anchor. Now he has to find the right way to get home.



Cash game, center cube.

(a) Black to play 2-1.

(b) Black to play 3-3.


In Part (a), we have to drop a blot somewhere. The only serious contenders are 6/3, 8/5, and 13/10. How do we choose?

When forced to leave a somewhat awkward shot, there are four criteria we examine. In no particular order, they are the following:

(1) How many shots do we leave?

(2) How good is the point that we’re starting?

(3) How stacked is the point we’re moving from?

(4) Does hitting cost our opponent anything?

Let’s take a look at just how these issues apply to our current position.

(1) How many shots do we leave? The winner here is 6/3, which leaves only 11 shots. Playing 8/5 instead gives White 14 shots, while 13/10 leaves 15 shots. How much weight we give to this factor really depends on just how much it hurts to be hit. Here it’s annoying, but it’s far from the end of the game. White has only a 3-point board, and no builders in position. Defensively, we have a good anchor on the 17-point. We don’t want to lose ground in the race, but we won’t be too badly hurt if we do. So while this criteria favors 6/3, it’s not an important factor in our decision. (If White had a 5-point board, it might be the most important factor.)

(2) How good is the point that we’re starting? Hands-down winner here is 8/5. The 5-point is obviously much better than either the 3-point or the 10-point.

(3) How stacked is the point we’re moving from? Slight edge here to moving off the bigger stack on the 6-point, but since all these points have at least two spares, this consideration isn’t a big deal.

(4) Does hitting cost our opponent anything? This last criterion is decisive. White is delighted to hit with the blot on his 23-point, but breaking his 18-point anchor to hit on Black’s 10-point is a big price to pay. Not only does White break a great defensive point, but he may leave two more blots in the process. Breaking the anchor to hit is enough of a price for White to pay that it outweighs the value to Black of starting the better 5-point, making 13/10 a narrow winner.

When forced to leave shots, pay attention to your opponent’s stacks and stripped points. You’re relatively happy to leave a blot in front of a point with no spares, since you can force your opponent to make a concession in order to hit. Be less eager to leave a blot in front of either a blot or a severely stacked point, since your opponent will be eager to hit.


Part (b) is fairly straightforward. The right play is 8/5(2) 6/3(2), which was also the consensus choice by a wide margin. This play makes the two best points available and gives Black an instant board with some threats against White’s rear checker. A play like 13/10(2) 6/3(2) unstacks and makes some good points, but doesn’t have the same attacking power as making two inner points.

There were a couple of players who picked 17/11(2), which is an interesting play. It looks appealing because Black will lead by 14 pips in the race after he plays (136 to 150 for White), so the idea of disengaging is attractive. While generally you want to disengage when you’re ahead, you have to be careful if your home board is undeveloped. Black is surrendering his rear anchor with this play, and if he subsequently leaves a blot and gets hit, he’s in real trouble. Whether this play is good or not really just depends on the strength of Black’s home board. When his board is undeveloped, as here, this play won’t work well. If he had a good home board already, this play would probably be the right choice.

Solutions:

Part (a): 13/10

Part (b): 8/5(2) 6/3(2)