Defense: What do you lead after taking partner's opening lead?

Here’s your hand sitting North, and the bidding:

♠ 82

♥ AKQ864

♦ 96

♣ 1097

West          North   East   South

 P                2H     3S      P

All Pass

Partner leads the JH

Here’s the dummy (on your right):

♠ Q7

♥ 53

♦ KQ432

♣ J652

You take the Queen and declarer discards the 10. What do you return?

If you said that you would take the second heart immediately you probably lost the hand. Partner’s lead of the jack must be either a singleton or a doubleton because declarer discarded the 10. That is probably a false card, to keep you from continuing hearts. If partner has a doubleton (probably), that means that declarer has three hearts and will lose all three unless she can trump your third heart lead. There are two trumps on the board. You want to get a third heart trick so you want to get the queen of trump off the board.

So the answer is that you must lead a trump. Even if declarer has the ace, she has to lead another heart to be able to trump with her queen and you can take it and lead your last trump to get rid of the last trump on the board, so she’s stuck with a losing heart in her hand and she goes down one.

Here is the four hand layout

North

                        ♠ 82

                        ♥ AKQ864

                        ♦ 96

                        ♣ 1097

West                                        East

♠ Q7                                        ♠ KJ109653

♥ 53                                         ♥ 1092

♦ KQ432                                 ♦ A

♣ J652                                     ♣ AQ

                        South

                        ♠ A4

                        ♥ J4

                        ♦ J10875

                        ♣ K843

This is a real unfortunate hand for east because she has only one possible entry to the board, and that’s the heart ruff which you denied her. She can take her ace of diamonds, then the A of clubs, then leading the club Q to south’s king and she’s got good cards in the minor suits to get rid of her heart loser, but she can’t get there after you take out her trump.

When this was played in a club game, three declarers made either three or four because defenders failed to play trump early to keep declarer from ruffing a heart and discarding her losers on the diamonds. If north never leads a trump, the hand easily makes four. Since partner has the ace of trump even if north takes both hearts immediately, if he then leads a trump partner can take the ace and lead another, getting rid of both trumps on the board.

But north should not count on that. The safest and best play is to lead a trump immediately before taking the second heart because if declarer has the trump ace and takes the return, she still has to lead another heart to get rid of the last heart on the board and north can take that trick and lead the second trump. If he takes the second heart immediately and then leads a trump it’s too late because the board is now void of hearts and if declarer has the trump ace (a better than 50% chance) declarer can take the belated trump lead, play the diamond ace and trump his third heart to get to the diamond king and queen to rid himself of his club loser.

Played correctly, NS should take three hearts, the spade ace and the club king, five tricks for down one in a 3S contract.