A Very Specialized Reason

	J 10 5 2
	K
	A 10 9 5
	A 8 7 5
6		K 9 7
Q 5 4		J 10 8 3 2
K Q 7		J 8 5 4
Q J 9 6 4 3		10
	A Q 8 4 3
	A 9 7 6
	6 2	Contract: 4 spades
	K 2

Four spades, opening lead from West: the queen of clubs. Declarer wins in the closed hand, goes to his king of hearts and draws trump in three rounds with a successful finesse. He now cashes the ace of diamonds, loses a diamond and winds up making 6! How'd he avoid a heart loser, I wondered. He did take three rounds of trump in quick order, so he could ruff only one. Well, there it was: Declarer didn't just "lose" a diamond. He led the 10 of diamonds, covered by East!

Yes, declarer lost a diamond, but he got a lot of stuff with his 10, namely the J and the Q! On a club continuation, declarer wins with the ace, ruffs a diamond, dropping the K, of course, and now on a heart ruff, he has a good diamond on which to sluff a heart.

Don't cover the first of equal honors! Well, okay, there are exceptions to that basic rule, discussed here, but there are so many reasons for not covering the first of equals that your orientation should be for the non-cover until you have reason to cover (principally, a doubleton honor). But here, common sense might have told East to lay off even if he never heard of equal honors. After the ace of diamonds, there are only 3 diamonds out that East can't see and two of 'em are the K Q! Now, if they're split 2-1, one of those honors has to be played on the next trick and your jack, which might be valuable if you save it, can't do a thing on this trick. And if the 3 remaining diamonds are in the same hand?

Well, if West has all the rest and declarer started with a singleton, then the jack won't do any harm. But suppose it's declarer who has the remaining diamonds? Then it should be obvious that the play of the jack gives the diamond suit away. If East ducks, declarer has to come up with a pretty good guess. And if he doesn't? East then sits with J 8 over the 9, and declarer must lose a diamond trick.