There is no magic rule that tells a defender when to cover an honor with an honor. The fact is that while it is usually best to cover an honor when declarer seems about to finesse, there are times when it is better not to do so.

Basically, the governing principle is to cover when it seems advantageous to do so, and to play low when it seems disadvantageous, but this advice is not very helpful because it leaves a great deal to the discretion of the player.

Consider this deal where South wins the diamond lead with the ace and returns the jack of spades. Should West cover with the king or not? Clearly, the answer is yes. First, let’s assume West ducks. Declarer wins, leads another spade and makes five spade tricks as well as four notrump.

Now let’s suppose West covers the jack and that declarer wins with the ace and continues with the Q-10, hoping for a 3-3 division. When this fails to materialize, South scores only three spade tricks and winds up down one. The outcome is directly traceable to West’s covering with the king, which in turn promotes East’s nine into a stopper.

West covers because he cannot benefit in any way by ducking but is sure to gain at least one trick if he covers and East has any four spades.

It should of course be mentioned that if West covers the jack as he should, South has an effective countermeasure available. He simply allows West’s king to hold the trick, refusing to stake the outcome solely on a 3-3 division. Allowing the king to hold guards against the more likely 4-2 break and enables South to score the four spade tricks he needs to make the contract.

Tomorrow >> Famous Hand.

— Steve Becker