My most frequent correspondent is Steve Conrad, of Manhasset, New York. He has a good eye for an instructive deal, so this week let’s look at a sextet of them.

First, we have a defense that requires deduction and disobeying the textbook. It is not as straightforward as it appears when you look at the full diagram.

Against three no-trump, West was right to lead his fourth-highest heart, not the queen. Only lead an honor from three touchers (Q-J-10) or two touchers and a gap of one card to a near-toucher (A-Q-J or Q-J-9).

South plays dummy’s king in the hope that West holds the ace.

Now the spotlight falls on East. The textbook says that if you win the first trick, you return the lowest from three remaining cards (or the higher from two). Here, though, if East leads back the heart six, it blocks the suit. West wins with his jack and plays another heart, but East can take only two more tricks with his 10 and eight. South then claims nine winners: two spades, two diamonds and five clubs.

From the Rule of Eleven (4 from 11 is 7), East knows that South started with only one heart higher than the four, which must be the jack (declarer mis-guessed at trick one) or the nine. If it is the jack, South must have begun with only two hearts; otherwise, he would have played low from the dummy at trick one to guarantee a heart trick. So, East should lead back his 10. Here, he wins the trick and plays another heart. But if South could cover the 10 with the jack, West must make that deduction about jack-doubleton and lead a low heart at trick three, not cash his nine from an original Q-9-5-4-3. Tough.