One of the reasons why contract bridge is the most challenging of all card games is that after you have learned how there is still the problem of when. And where. And why. To the avid student, learning the answer to "why" can be the most revealing method of instruction. Here, for example, is a hand that turns out to be a complete question box. But if you ask yourself the right questions you are very likely to come up with the right answers.
South opened with one no trump and North knew at once that game should be bid because his total of 11 high-card points guaranteed that his side held more than the 26 combined points needed. His Stayman bid of two clubs explored the possibility of a heart fit, and when South bid hearts North jumped to game in the suit. But even though the combined North-South total was 29 points, including two for distribution, this was no guarantee that a game bid would succeed, especially if declarer were guilty of less-than-perfect play.
South began well enough when he declined to cover the opening lead with dummy's queen of diamonds. If West were leading from the king, there would be time enough later to play toward dummy's queen, and a diamond trick would be lost in any case.
When East played the king of diamonds South had reason to congratulate himself. He needed only two diamond tricks to insure his game even if the heart finesse failed. So he grabbed the diamond ace, crossed to the ace of clubs and led the 10 of hearts for a trump finesse that might provide an overtrick if it succeeded. Unfortunately for South, the finesse lost. Back came the 10 of diamonds. South saw no point in holding up dummy's queen; West could simply continue the suit. East trumped the queen of diamonds, and although declarer was later able to ruff his losing club, he could not avoid losing two more diamond tricks and his contract.
"I shouldn't have taken the heart finesse," South mourned. "But the safety play—ace and another heart—doesn't work either. East still has a trump to ruff out the queen of diamonds."
"But you could have made it," his partner countered, "if you had ruffed out your third club and dummy's third spade before you led the ace and another heart. Then, when East trumped the diamond queen, no matter what he returned you would have been able to discard one of the diamond losers from one hand while you ruffed in the other. That way, you'd have got the trick back."
"True," South admitted. "But suppose somebody had held four trumps to the king. That line of play would have cost the contract."
Nevertheless, South had given the contract away by not asking himself why and how before he played to the very first trick. Why had East played the king of diamonds? Obviously because it was a singleton. How could South insure the contract in that case? The answer: let the king of diamonds hold the first trick. Declarer can then afford to take the trump finesse. If it loses, West can return a diamond and East can ruff. But South does not have to play a high diamond from either hand on the trick East ruffs. He collects his two high diamonds later, losing only two diamonds (including a ruff) and a heart to make his contract.