In this article we are taking a look at a pretty simple problem but one that many people (including myself) get wrong.

What should blacks play be ? There are three options

(A) 20/14, 7/3

(B) 7/1*, 7/3

(C) 20/10

Before reading further take at few minutes to decide how you would play the roll and why.

Now let us look at the relative merits of each option:

(A) frees one checker out from behind white’s mini prime (note that 9 of black’s numbers will not let him move any of the checkers on his 21-pt). It also creates a five-point prime against white’s single back checker. On the downside any 6 by white will be a winning roll as he holds the doubling cube and can probably play on for a gammon without much risk. White does have some horror numbers in 55, 54 and 44 and 22 isn’t great.

(B) also creates a five-point prime but has the bonus advantage of putting white on the bar against a five-point board. The negative side of this play is the fact that there are still three black checkers partially trapped on white’s 4-pt.

(C) This will solve the problem of the three trapped checkers by freeing one of them. It gives white some additional bad numbers. Now 64 and 61 also leave black with a direct shot. The downside of this play is that if white rolls a 2 he will have a winning position unless black manages to re-enter immediately.

So which is the right play to make ? As with many decisions in backgammon it is a question of balancing the risk against the possible reward. You need to balance your experience with detailed analysis.

I personally got this wrong by playing (B)

There are two key points to note about (A) & (C):

- They both results in allowing a back checker to escape. Computer analysis has taught us the importance of escaping from behind even a small prime.
- They will both allow white to leave another blot exposed with quite a few numbers. This will in turn lead to black winning more gammons – a factor that most people will have overlooked when doing their analysis.

(A) is the better option because, it is much easier for black to make a full prime after this roll than (C); it will win more gammons and it loses fewer gammons. In fact (C)wins it by a massive margin, just check the rollout numbers in the picture above.

C.Bray 2007