Declarer in today’s deal from the Common Game played three spades competently. Clubs were originally 3-3, so South could eliminate that suit and endplay the defenders with the third trump to hold his diamond losers to one. However, I have changed the layout in the minors to make the task for declarer more challenging.

The defense begins with two top hearts followed by a shift to the club jack. Declarer takes the club in hand and cashes both top spades, then runs the club winners as West discards a heart. When South leads the fourth club, planning to ruff this in dummy, West must pitch a heart. Otherwise, declarer can set up diamonds easily enough for one loser. So West pitches a second heart, and, after ruffing the club in dummy, South exits from the North hand with a trump to East’s queen. What four cards does West come down to now?

If he comes down to one heart and three diamonds, then East can do no better than lead a heart, and declarer discards a diamond to endplay West to lead away from the diamond king or East from the jack.

But if West pitches a diamond, to come down to two diamonds and two hearts, declarer ruffs the third round of hearts and leads a diamond to the 10 and jack. East has only diamonds left, so he leads one, and South plays low from hand. When the king pops up, declarer has the last two tricks.

This line may require playing East for the diamond jack, against perfect defense.

Bidding over pre-empts is more about judgment than science. Here, South should not double a three-diamond pre-empt, since he cannot stand to have partner bid spades at just about any level.

When North raises to four diamonds, suggesting at least a good high-card raise to four hearts, South might stretch just a little and use key-card, hoping his extra shape in the side suits will come in handy, as indeed it will.

After the lead of the diamond 10, declarer should not put up the diamond queen, since doing so might provide the defenders with some communications. He will win the first diamond in hand and lay down the heart ace, then draw trumps and pitch his diamond loser on dummy’s good spade. Now he can ruff a diamond to hand and reach a five-card ending where he has four clubs and a trump in each hand. Can you see what he should do next?

If clubs are 3-2, the hand is cold for 12 tricks. If clubs don’t break, then declarer cannot protect himself against West having begun with all of the four significant spot cards. But he can guard against East having a singleton intermediate or honor in clubs by leading a small club from hand and playing low from dummy, no matter what West plays. In the layout shown, if West plays low, then East will win his 10 and be forced to surrender a ruff-sluff. If West plays high on the first club, he is left on lead; now, whether he plays a high club or a low one, declarer is home.

West leads the club three against four spades, and South can see that he must expect to lose a club. He can discard one of his hearts on a club and ruff his other losing heart with one of dummy’s small trumps. He should then be in good shape to hold his spade losers to two at most.

When East wins the ace, South drops the king from hand to create an entry to dummy. That will allow him to win the next club in dummy rather than in his own hand.

East returns a low spade, and South can afford to put in the jack, since he needs only one trump in dummy to ruff with. When West wins trick two with the spade queen and returns a diamond, South wins dummy’s king rather than risking the finesse. South also cannot afford to take another trump finesse immediately, since West might be able to win and return a third trump to keep South from ruffing his losing heart at all.

To avoid this fate, now is the right moment to take the spade ace, then cash the two club winners in dummy so that South can get rid of one of his losing hearts. Next, declarer cashes the two top hearts and ruffs the fourth heart with dummy’s seven. Though East is out of hearts, he cannot over-ruff, and even if he could, it would be with the master trump.

Only now can South afford to resume the play of trumps. He concedes one trick to the defenders’ master trump but makes his contract.

When you reach the normal contract of four spades, you have been warned that diamonds may not break, but at least the shortage will be in the right place. After the diamond five is led, you capture East’s queen with your ace. How should you continue?

The best chance seemed to be finding the heart ace with West, or perhaps the spade king with East. So you lead a heart at trick two, which goes to the king and ace. Back comes the spade two, and now you must revise your plan. Be warned: the answer isn’t easy! The point is that if you ruff two diamonds in dummy, West may score two trump tricks, and you will still have a diamond loser left.

The best line is to win the spade ace, then lead a club to the ace and ruff a club. Trump a diamond in dummy and ruff another club to hand. At this point, you lead one more diamond, and West can do no better than throw a heart. You ruff yet another club to establish dummy’s fifth club, and when West follows, that marks him with an original 3=4=2=4 shape.

You can now endplay West by leading the spade queen, throwing a low heart from table. (If you lead the spade nine, then West might meanly hop up with the king and exit with the spade 10, leaving you with two diamond losers.)

Note that as the cards lie, West can take your spade queen with his king and cash the spade 10. However, he must then lead a heart to dummy’s king, after which the club 10 is the game-going trick.

When this deal came up, two declarers were confronted with the same defense but drew two different conclusions from their opponents’ play.

At both tables, after the lead of the heart queen to the king and ace, each defender accurately shifted to the club king to try to set up tricks in that suit. At the first table, declarer won his ace and played a low spade to the king. When East discarded a diamond, declarer unblocked diamonds, then played a heart. However, West could now maneuver to score two trump tricks and a club.

At the second table, declarer read the lead as a singleton and asked himself why East had not played for heart ruffs. South concluded that West probably had a trump trick, and that East believed he needed more than just one heart ruff to beat the contract.

So, at trick three, South led the trump jack from hand and let it run when West played low. Then declarer took the trump ace and king before playing a low heart to the jack. Had West overtrumped to lead two rounds of clubs, declarer would have ruffed out the hearts, using the diamond king as a re-entry to dummy. So West discarded a club instead. Now declarer returned to dummy with the diamond king to run the heart nine, covered with the 10 and ruffed in hand.

West did his best by over-ruffing with the queen to cash a club, but declarer had the rest. He made four trumps, two hearts, two diamonds, the club ace and a club ruff.

Today’s deal comes from the semifinals of the Australian National Open Teams; it is the flip-side of yesterday’s deal. We had pointed out that declarer’s false-cards will occasionally rebound. But the advantage of these maneuvers is that fooling your partner does no harm when he is dummy.

Frequently, you want to prevent an opponent reading from his partner’s lead as a singleton and giving him a ruff. But occasionally, it is in your interest not to falsecard, as here.

Jacek Pszczola, known to the world at large as Pepsi, over-called four spades over an off-center three-diamond pre-empt. When West led the diamond nine, Pepsi played low from dummy; East put up his ace and saw the two from South.

East could read that his partner had led a singleton, so he returned a diamond, and West ruffed. Back came a heart, which Pepsi took with his ace. He cashed his two top trumps, then crossed to the club ace to dispose of his heart loser on a diamond winner. West could ruff in with his master trump, but declarer had the rest.

At the second table, West also led his singleton diamond against four spades, but this time declarer dropped his jack under the ace. Jacek Kalita, as East, was in the hot seat, and he could not read whether the lead was a singleton or doubleton. But he could see that his side needed to set up heart winners. So, he shifted accurately to a low heart at trick two, and now the contract could no longer be made.

The art of falsecarding is a complex one; it is generally a good rule as declarer to conceal small cards in the suit led to make the defenders’ task of reading leads and signals more difficult. But you should not do this entirely at random; sometimes you make the defenders’ task easier, not harder.

For example, in this deal from Masterplay (also known as the Expert Game) by Terence Reese, a false-card by the declarer was the clue to the defense.

West kicked off with the heart three against three no-trump. While some prefer to lead second highest rather than a low card from four small, leading fourth best was certainly reasonable. Declarer played the heart two from dummy, East played the heart king, and South dropped the heart nine.

South’s idea was to make the opponents think that he was short in hearts and to encourage a heart continuation. In fact, the play conveyed a completely different impression. East could tell from the lead of the heart three, with the heart two in dummy, that West had only four hearts. Therefore, South’s play of the heart nine had to be a false-card, and the inference to be drawn was that declarer was well upholstered in that suit.

So, East switched to a low diamond, playing his partner for the diamond jack. This play did the trick. When West came in with the spade king, he was able to return a diamond to his partner’s A-10 for the defense’s fifth winner.

After North’s Drury two club response to show a maximum pass with fit, South checked for key cards, then bid the spade slam.

West’s lead of the diamond 10 went to dummy’s ace. Declarer needed to hold his losers in the black suits to one, but had to decide which black suit to play first. In these positions, it is sometimes right to go after the side suit first, but here South advanced the trump jack and let it run when East played low. West’s discard of a low heart gave declarer pause. Can you see a good plan for him now?

Declarer’s solution was to throw a club on the diamond ace, then to lead out dummy’s trump 10, covered by the king and ace. Next, he put the club jack on the table — a move that would guarantee the contract as long as East had at least two clubs.

As the cards lay, the defense had no answer to this line of play. If West took the trick with the club queen, declarer would use dummy’s club 10 as an entry to pick up East’s remaining trumps. He would end up with six trumps, a heart, two diamonds and three clubs.

At the table, West allowed the club jack to hold the trick. Declarer continued by cashing the club ace, then ruffing the club eight in dummy. East overruffed this with the seven, but that was the only trick the defense made. Declarer ruffed the return of the diamond queen and drew East’s remaining trump with the ace, after which his hand was high.

When an opponent is faced with a blind opening lead, do you think it more likely that he has underled a king or a jack? Sometimes the fate of a contract will hinge on such a guess, but often declarer can survive guessing wrong — if he is careful.

Take today’s deal, where you drive to four spades on an uninformative sequence and receive the lead of a low heart. Your immediate reaction might be that if West has underled the king, you must fly up with the queen; while if he has underled the jack, you should play low. Is that addressing the problem correctly?

No, it is not, and the reason is that declarer’s heart 10 plays a huge role in the deal. Without that card, you would indeed put up dummy’s queen, but not today. Imagine that you play low from dummy and guess the position incorrectly. East’s jack forces your ace, but all is not lost if you win the lead and return the suit. West will win with his king and can shift to diamonds, but you have time to put up the king and lose the spade finesse to West. You will win the diamond return, shake a losing diamond from dummy on the heart 10, then ruff a diamond in dummy and draw trumps for your 10 tricks.

If the opposing heart honors were switched and you put up the queen, you would lose the chance to build a home for your slow diamond loser on the hearts.

Incidentally, if the first trump finesse succeeds, make sure not to repeat it until you have taken your diamond ruff in dummy.