Backgammon

IN THE Strand Magazine Tournament of 1899, Watson was drawn against the fiendish Moriarty. Early in the match, playing black, he had to decide how to play 61.

Since Holmes had often expostulated on the strength of a 5-point prime, he decided to risk leaving a blot on his mid-point and played 13/7, 8/7. The denouement was swift. Moriarty hit with a 41 playing 13/12*, 22/18. Watson entered with a 53 playing bar/ 22, 6/1 and two rolls later had to drop Moriarty's redouble.

Later, showing the position to the great detective, he bemoaned his luck. "Luck, Watson, has nothing to do with it," said Holmes. "I am afraid that once again you have let a general principle interfere with your analysis of a position.

"Five-point primes are all very well, but what is black's objective here? Surely his main priority is to escape his back man. Once that has been achieved he should win easily. This would indicate that the correct play is 24/18, 6/5. A tactical point, which should help you to conclude that this is the right play, is that if Moriarty hits your blot on his bar point with a 1 or a 2, he must break a good point to do so. In this instance, escaping the back man takes priority over building what might be a very short-lived 5-point prime."

"As ever, Holmes, your explanation makes everything seem so simple." "How complimentary, my dear Watson."