I played with a good intermediate player for a couple of years and we had some good games. She had decent technical skills, but for some reason she was loath to cover honours in certain situations, notably when declarer played the jack toward the A-Q in dummy. Just about every time it came up, I was sitting there with three to the 10 in the suit.

When I commented, she said, “But what if he has the 10?” In that case, there’s nothing to be done. Declarer will win the ace, queen and 10 in the suit. Yes, declarer made a bad play by tabling the jack. If declarer played low to the queen and my partner started with a doubleton king, there would be three tricks available. Playing the jack would compress them to two. If you want to succeed at this game, you must learn when it’s right to cover and when it’s not. There are occasions when it’s not right to cover. Here’s are a couple of them: Dummy has Q-J-9 and you hold three to the king. When declarer calls for dummy’s queen, you should play low. Do you see why?

(1) If you cover the queen, declarer will win the ace and then have a finessing position against partner’s 10. If declarer has the 10, it won’t matter when you cover. If you play low and declarer does not have the 10, he might play the jack next, hoping that your partner started with a doubleton 10. In that case, it would go jack, king, ace,10 and dummy’s 9 would be good. If partner’s 10 was not doubleton, it will be promoted to a trick if declarer plays the jack next and you cover. If you have the doubleton K-10, you must cover and hope that declarer finesses your partner for the 10.

(2) Dummy has A-5-4-3 and you hold Q-9-6. Declarer plays the jack, possibly fishing for the queen with a holding of K-J-10-x in hand. If you play low smoothly, declarer may go up with the ace and play your partner for the queen. If, however, declarer’s holding is something like J-10-8-2, you must play low to assure your side of two tricks in the suit.

Say you cover the jack with the queen. Declarer wins the ace and plays a low diamond from dummy. Your partner, holding doubleton king and must play it. Now declarer’s ²10 is good. You win one trick. If you play low on the lead of the jack, partner will win the king and you will have the Q-9 remaining. When declarer leads the suit again. Your 9 will knock out the ace and your queen will be good.

Here’s a card combination that many new players overlook. Say you are in 4 and have lost three tricks but have no other losers outside of trumps. You are in dummy for the last time and have this trump holding:

 J 9 4 3
 A Q 10 2

You cannot afford a loser in this suit. How will you play it?

Obviously, the king must be on your right. You can protect against four to the king by starting with the 9. It holds and you are still in dummy. Now you can play the jack and let it run if RHO plays low. You are still in dummy and can finish off the suit by playing low to the queen. If RHO covers the 9 or jack, your high spades will take the rest. It doesn’t work to play the jack first. If you don’t unblock the 10, you will be in hand after a second finesse and the 4-1 break will beat you. If you unblock the 10, East will certainly take a trick because you will be stuck in your hand or RHO will cover the 9 to assure himself of a trump trick.