Bridge

A concept defenders must understand is that of keeping “parity”: saving equal length as declarer in suits he may use for tricks.

At today’s 3NT, South ducks East’s queen of clubs, wins the club return and exits with a club, letting West take his tricks -- and obliging East to find discards. On the third and fourth clubs, dummy discards a heart and a diamond.

East knows from the bidding that South had four cards in hearts, and dummy has four spades, so East can’t spare a card in either suit and must pitch two diamonds. To unguard the queen is unpleasant and counterintuitive, but East must keep parity in both majors.

That is not the only issue for the defense. If West takes his last club, he “rectifies the count” for a squeeze. East can discard his queen of diamonds, but when declarer gets in, he will take the ace of diamonds, squeezing East in the majors. So at Trick Five, West should lead the queen of spades.

Against careful defense, 3NT is unmakable.