When to overruff; when to discard

[China Daily]

Last week, we looked at deals in which a defender had a chance to ruff in. Most of the time, it was right to ruff; but not always. This week, we move to overruffing. Occasionally, some guesswork will be needed. However, assuming that if you do not overruff, your high honor will still be a winner later, this basic guideline works much more often than not: Overruff with any singleton, doubleton king-low, doubleton queen-low, and with tripleton queen-low-low unless partner rates to be short in the suit; otherwise, discard.

Apply that to this deal. West is defending against four hearts. He leads the diamond nine. East wins with his queen, cashes the diamond ace, and continues with the diamond king. When South ruffs with the heart 10, should West overruff or discard?

I agree with East's one-diamond opening. With such a good suit, the hand was too strong for a weak two. He needed little from partner to be making three no-trump. South's overcall showed a weak hand with a decent seven-card suit, and North bid what he hoped his partner could make.

The rule says to overruff, and that works. East-West take two hearts and two diamonds. However, it must be admitted that if West does not overruff, the contract might still fail. South will play a heart to dummy's ace, return a spade to his ace, and then have to guess whether to lead a low heart (the king is now singleton) or the queen (the jack is now alone). But why give South a chance to get it right?