There are not many activities in life where knowing how to count to 13 is as important as it is in bridge. In fact, it’s often said that counting to 13 is really the name of the game. Today’s hand should provide proof for any doubting Thomases.
Declarer won the heart lead with dummy’s ace and could count 12 top tricks -- three in each suit. The 13th would have to come from either diamonds or clubs, and South knew the odds were very good that one suit or the other would provide him with the extra trick he was looking for. But rather than just proceed on the assumption that one of the two suits would divide favourably, South found a way to overcome the possibility that both suits would break badly.
His first step was to cash the K-Q of hearts, discarding a diamond from dummy. This revealed that West had started with six hearts. Declarer then led the A-K-Q of clubs, hoping the jack would fall, but discovered instead that West had begun with four clubs to the jack. To complete the picture of West’s hand before he tackled the diamonds, South next cashed the ace of spades and led a spade to the queen, noting that West followed to both spades. With 12 of West’s cards thus fully accounted for, it was now a simple matter to cash the diamond ace, lead dummy’s ten and, after East played low, let the 10 ride. A diamond to the king, followed by a spade to dummy’s king, allowed South to score the queen of diamonds for his 13th trick.
Observe that if South had played any two of his three top diamonds earlier in the hand, as many players might have done, he would not have made the grand slam. By utilising the magic number 13 from the outset, South wound up plus 2 220 points instead of minus 100.