When planning the play, declarer should seek the approach that gives him the best chance to make his contract. Unfortunately, the best chance is not always readily apparent.
Consider this case where West led a trump against six clubs. East took the ace and returned a club, leaving declarer with three potential heart losers. One of these could be discarded on a high spade, and another could be ruffed in dummy, but in order to get rid of the third heart, South had to establish an extra trick in one of dummy’s suits.
In practice, declarer first cashed the A- K of spades, revealing the 5- 1 division in that suit. He then led the K- A of diamonds and ruffed a diamond. When the opposing diamonds failed to divide 3- 3, he had to go down one, as there was no way to get rid of his third heart.
South erred by attacking the spade suit first. Although the spades were stronger, it was clearly better to tackle the diamonds initially. Had he done this, he would have been able to set up and then cash dummy’s fifth diamond, using dummy’s spades as entries.
How can South recognize this in advance? From the outset, his only real concern is a 5- 1 break in the suit he chooses to establish. As we have seen, if the spades are broached first and the suit splits 5- 1, South needs a 3- 3 diamond division to make his contract.
But if declarer goes after the diamonds first and runs into a 5- 1 break, he can still make the slam if the missing spades are divided 3- 3 or
4- 2. In the latter case, after testing for a 3- 3 spade break, declarer can ruff a spade, if necessary, to establish dummy’s fifth spade. A heart ruff then provides the re- entry to dummy, and the contract is home.
By attacking diamonds first, declarer thus gets three chances to make the slam instead of just two.