West leads the heart jack against three no-trump, dummy’s queen winning the trick, while East’s card is consistent with showing an even number of hearts. How should you plan to make your contract?

If you take the club finesse, West will win his king and drive out the heart ace, and you will be held to eight tricks. A far better approach is to assume that West has the diamond ace, so cross to your hand with a spade at trick two and lead a diamond toward the king.

If West takes his ace and continues hearts, you will win that ace and lead a low diamond, intending to cover West’s card. West has to follow with his six, and you insert dummy’s 10. After East wins the jack and shifts to a club, you rise with the ace and cross to the spade king to run the diamonds. You will take 10 tricks: three spades, two hearts, four diamonds and a club.

If West wants to prevent the overtrick, he must follow with a low diamond at trick three. You will put up dummy’s king and remain on lead to run the club 10 to West’s king. You will emerge with nine tricks: three spades, two hearts, a diamond and three clubs.

Finally, if West takes the diamond ace at trick three, clears hearts, then follows with an honor on the second round of diamonds, you will have to hope East started with three diamonds. You need to win the second diamond with the king, then cross your fingers and play a third diamond.

After a straightforward auction to three no-trump, South should count his winners when West leads the spade four. With at least six tricks coming from hearts and clubs and at least one trick in each of spades and diamonds, he seems to be in good shape.

At trick one, South captures East’s jack with his queen. Since West appears to have led from the A-10, it would be very dangerous to allow East to come on lead. East would then be in position to lead a spade through South’s king, letting West run spades and possibly defeat the game.

There is no such danger in letting West on lead. If West leads spades again, South can establish his ninth trick from the spade king. To put it another way, East is the dangerous opponent and West if the safe hand. If possible, South must develop his tricks while keeping East out of the lead.

Declarer begins by leading a heart to dummy’s king. If hearts break, declarer will have nine tricks without any need for further work — but that can wait. Declarer now goes after diamonds by running the diamond eight through East. If East has both top honors, he cannot be kept off lead; but in virtually every other scenario, it may be possible to develop diamonds while keeping East off play.

The diamond eight loses to the nine, and South wins the club return, then leads a heart to dummy and leads another diamond, covering East’s card. Declarer can then run the diamonds and cash out for nine tricks.

When North opens the bidding, South’s assets suggest inviting rather than driving to game. However, East’s jump to three hearts prevents South from bidding his hand scientifically. He might as well drive to four spades — the only question being whether to bid game at once, or to bid and rebid the suit.

In four spades, South can expect to lose two hearts and a spade, eventually discarding his low diamond on one of dummy’s clubs. East upsets the applecart by overtaking the heart king and leading back what appears to be an obvious singleton diamond.

South should now see the danger; if he makes the normal play of leading a trump, East will take the ace and lead a low heart to West! West will then give East a diamond ruff to set the game.

The way to circumvent East’s plan is to win the diamond king and go after clubs at once. If East can follow to two rounds (highly probable since he appears to have only one diamond), South is safe.

East does follow to two rounds of clubs. If he cannot ruff the third round South will discard the losing heart and be home free. When East ruffs in, South still discards his remaining heart.

This was a card South expected to lose anyway, so the play has cost nothing. The big gain is that now West cannot gain the lead; he can never give his partner a diamond ruff.

In effect, South has given the enemy a trump trick instead of a heart trick. By doing so, he has cut their lines of communication.

This board came up in the Common Game pairs recently, and I was lucky enough to be minding my own business as East when declarer proved yet again that greed is a terrible thing.

South had done well up to a point to open low and not drive beyond the four-level when her partner raised hearts. My partner tried a low spade lead, and declarer immediately cashed her black winners, then led the ace and another heart. My partner took the king and played a third heart. Declarer cashed the spade king to pitch a diamond, then ducked a diamond to the bare king, but now the defenders had plenty of exit cards, and declarer lost three diamonds and a trump for down one.

Paradoxically, there are good chances for the overtrick against most lies of the cards if the trump finesse succeeds, as long as declarer remembers that when you want to ruff, it is a bad idea to play trumps. Simply win the spade lead and cash the club honors, then the diamond ace, planning to exit in diamonds, and force the defenders to give you an entry to dummy for the trump finesse.

The sight of the diamond king should not dissuade you from this strategy. Play a second diamond, and East will cash two diamonds, West pitching spades, then will lead a second spade. You can ruff with a trump intermediate, planning to lead out the diamond jack and subsequently cross to dummy to take the trump finesse. At the very worst, you will be sure of 10 tricks.

Against your delicate six-heart slam, West leads the spade two, an apparent singleton. Can you find any way to make your contract?

The layout you need to make 12 tricks will require West to have a doubleton rather than a tripleton heart. Win the opening lead with the spade ace, then cash the trump ace and king. Next, play a low spade from dummy.

Since you can expect to encounter good defenders in my problems (if not always in real life), East is likely to duck; so your jack will win the trick. After crossing back to dummy with the trump queen, you ruff a spade. Then, after a diamond to the ace, you concede a trick to East’s spade king. East will no doubt shift to a club, which you will win with the ace. You can then throw dummy’s remaining club on your diamond king and claim the rest of the tricks, since dummy is high. You make four spades plus a ruff, four trumps in dummy, and three winners in the minors, for a total of 12 tricks.

Notice that you could not afford to draw a third round of trumps. If you had done so, East’s playing low on the second round of spades would leave you one entry short of being able to set up and cash the spades. You needed three entries to dummy: one to ruff a spade, one to concede a spade, and the final ruff to reach the winning spades in dummy.

Also, if West starts with three trumps and a singleton spade, then the contract cannot be made against best defense.

Against three no-trump, West leads the spade two (low from three small in partner’s suit), and East plays the nine. How do you plan to make your contract?

If you win the first trick with the spade queen and go after diamonds, West ought to rise with the king to play a second spade. After you win the spade ace and discover that the hearts are not breaking, you will have eight tricks, but no more.

The way to avoid this unpleasant outcome is to duck in hand at trick one. If a spade is continued, you should follow low again. If East plays a third round of spades, you will cover that card and win the trick. When you play the diamond 10 to the next trick, West will win the trick with his king, but he will have no spade left to play. After winning the heart exit, you will play a second diamond to dummy’s queen and East’s ace. At this point, you can claim nine tricks: two spades, three hearts, a diamond and three clubs.

You should observe that if East doesn’t continue spades at trick two or three, you will be able to develop two diamond tricks to make your contract.

The justification for this line is that it looks like the spades are 3-5, and you need East to have the three missing spade honors. As most players would open the bidding if they had the diamond ace and king as well as this hypothetical spade suit, you should play on that assumption.

West has no reason not to lead the heart jack against three no-trump. South wins the first trick with the king and leads the diamond jack, losing the finesse to East. What should East play next?

It looks natural to return a heart, but if partner has one more entry, the lead of a low club will eventually ensure three tricks in the suit; and if partner cannot gain the lead, the game will surely not be defeated.

So at the third trick, East returns a low club, knowing that if he can subsequently manage to put his partner on lead to play back a club from his side, it will suffice to set the contract, always assuming that he has two or more clubs. It would be a mistake to shift to the club queen, since that would be fatal if South had four to the 10.

After the return of the low club, South is helpless; he can do nothing but drive out the diamond ace, and West holds off until the third round, to see East’s discard. When East pitches the spade two on the diamond ace, it should be clear that he wants a club return, and that will suffice for the defenders to take two diamonds and three clubs.

The fact that declarer took a first-round finesse in diamonds is somewhat indicative of the fact that he may be missing the ace. If declarer were missing a different ace (say, the heart ace), declarer would be more likely to win the heart queen at the first trick and finesse in diamonds against East.

Over the last four years, an elite annual bridge tournament for women has been organized in Beijing. The Hua Yuan Cup is for eight national women’s teams, and today’s deal comes from the main event.

Poland’s Justyna Zmuda had the opportunity to find a sparkling defense after an unusual sequence. While the jump in a minor suit opened on your left can be played as natural, typically a jump bid in the suit the opponents have opened asks your partner to bid three no-trump with a guard in that suit. The call is usually based on a long, solid minor suit, plus guards in at least one of the other two suits.

On lead against three no-trump, Zmuda started with the spade ace in order to get a look at dummy. East followed with the spade five, and South with the three. The auction showed that South had started with a spade stopper — probably queen-third or queen-fourth.

Zmuda took heed of East’s five and decided that unless East had started with the doubleton 5-4, it was consistent with a suit-preference signal for diamonds, the lower of the red suits. And since she needed less from her partner in diamonds than she did in hearts, she made the killing switch to the diamond jack, though today the diamond king would have worked equally well. (That would not have been the case if partner had held the doubleton A-9 or A-10.)

The defenders could now cash five diamonds and two spades for three down.

Today’s deal, based on a recent Common Game deal with the club honors slightly altered, sees East use a defensive technique that everyone should know. It may seem obvious when you see the point, but at the table, the intermediate player who was faced with the problem did not see the solution.

North used Stayman, then settled in three no-trump when he did not uncover a four-card spade suit opposite. West led a top diamond; declarer won and passed the spade jack. East won cheaply and shifted to a low heart. When declarer guessed correctly to play low, it forced the king, and declarer now had nine tricks without breaking a sweat.

Notice the difference if East shifts to the heart 10. Whether South ducks or covers, the defenders will be in position to run the hearts when they regain the lead with the spade ace.

This concept of leading a high card to squash a doubleton or tripleton spot-card in dummy has more than one variation. (The play would work equally well if the heart two were in dummy rather than in East’s hand.) It may be right for East to shift to the jack from A-J-9 or K-J-9 if there were a doubleton or guarded 10 in dummy, for example. When declarer has queen-third, this will allow the defenders to run the suit on defense.

Of course, in our example hand against a good defender, maybe you should assume East is more likely to have the K-Q than Q-10 or K-10 when he shifts to a low card!