Today’s deal sees a very neat defense against a three-no-trump contract from a pairs event at the end of the most recent NEC tournament in Yokohama last year.

Dawei Chen, playing with Takahiko Hirata, found the natural lead of a low spade to his partner’s king and declarer’s ace. South led a diamond toward the ace, and Chen played the jack. Declarer took the ace and led a diamond back to the nine and Chen’s 10 (probably an error in theory as well as in practice, since your best chance of playing diamonds for one loser is the actual layout). That gave the defenders a slim chance of success, and Chen was quick to take advantage of it.

He sensibly inferred that for declarer to be playing on diamonds rather than clubs, he rated to have a singleton club. So he shifted to a low club, and Hirata did extremely well to play low. The bare club ace was forced to take the trick, and declarer played a third diamond, letting Hirata win and unblock his club jack as South pitched a spade. Now East advanced a heart honor, which was ducked all around.

Hirata now exited with his second top heart to lock declarer either out of his hand or dummy. The best move for declarer would have been to win the third heart in hand with his nine, but he would then have had to concede trick 13. Declarer ran the hearts from the top and finished two down, representing a top for North-South.

After North’s Texas transfer response followed by Roman Key-card Blackwood, West knew to go passive on opening lead, so he put a trump on the table. Declarer counted 11 top tricks and saw that if trumps broke, he could arrange an elimination play. He would draw trumps, cash the hearts and play a diamond to the queen; if that lost, West would be endplayed.

South won the lead and drew a second round, realizing his hypothetical elimination play would now not work. So he drew the last trump and was about to go after diamonds when he realized that he might as well cash his hearts first. He took the three top hearts, then led a diamond to the queen.

West won his king but had no heart to lead. Since declarer was marked with the club queen, he could do no better than exit with the diamond jack, hoping his partner would produce the 10. But declarer could win his ace and throw a club on his good diamond 10: He ended up with six trumps, three hearts, two diamonds and a club to make his contract.

Notice that if declarer had failed to cash the hearts, the contract would have failed, since West would then have had a safe exit in hearts. As the play actually went, if West had had the fourth heart to lead after winning his diamond trick, declarer would ruff, then play the diamond ace and ruff a diamond. If the diamond jack had not fallen, he would have taken the club finesse as his last chance.

The best conventions are those that come up relatively frequently, are easy to remember and don’t require you to sacrifice a useful natural call to implement. Well, as Meat Loaf said in discussing Lebensohl, “Two out of three ain’t bad.” Lebensohl is an eminently forgettable concept, but once you have it in place after intervention to one no-trump, you can also use it in other relatively common sequences. Today’s auction is a case in point: South would have bid two no-trump, a puppet to three clubs, to show a weak hand with his own suit. His direct three hearts is encouraging, but not forcing (7-10 high-card points with either four or five hearts), and North has an easy raise to game.

The defenders cash two top spades, then shift to the club two. While this could be a singleton, East’s initial pass makes this somewhat unlikely. You win with the ace, ruff a spade in hand and lead a club to the king. When West follows up the line, you ruff dummy’s last club with the heart 10.

Having found West with six spades and three or more clubs, you cash the diamond king and lead a diamond toward the ace. You know that if West were to trump in, he would be ruffing a loser, and you would have the rest. When West follows twice, you know 11 of his cards. So, next play the heart ace and lead a heart to your nine. If it loses, West must give you a ruff-sluff; if it wins, draw the last trump and concede a diamond trick.

In today’s deal, South has too much to pass his partner’s rebid of two spades. But since no-trump could easily be the right final resting place, he explores first with three clubs, then cue-bids the opponent’s suit, suggesting half a heart stopper. North looks with favor on his good controls and drives to four spades.

Now the spotlight turns to East, who must abandon traditional thinking. When West leads the heart four, the partnership methods are to play third and lowest. What that means is that West leads low from an odd number, top of a doubleton, but third highest from a four- or six-card suit.

After winning two heart tricks, East can infer that because West led his lowest heart, he has precisely three cards in the suit. (This inference is one not always available when playing fourth-highest leads.) What should he do now?

East has two potential club tricks with which to defeat the game, but will not make both if South establishes dummy’s diamonds for club discards. If declarer has the diamond queen, the defenders are helpless. But East must hope that is not so. To forestall the chance that dummy’s third trump might constitute dummy’s late re-entry, he must force dummy to ruff the third heart.

Should declarer then play to establish diamonds via a third-round ruff, East must save his club ace to take down the king. He must not capture the queen if South leads it out of his hand to tempt him.

South’s balancing double of one spade followed by the two-heart call suggests a good hand, but not necessarily a great one. He rates to be in the 15-18 range with five or more hearts, so he certainly has enough in hand to accept North’s invitation to game.

When West starts with three rounds of spades against four hearts, South ruffs the third and must make a plan. Since East has produced the spade queen, declarer knows he is unlikely to have much else in the way of high cards.

Declarer’s task is to limit his minor-suit losses to one trick. If he could count on the diamond finesse to win, he could simply concede a club. But the diamond king is almost certainly in the West hand.

The better plan is therefore to try to develop two diamond tricks in dummy for the discard of South’s two low clubs. At trick four, South should lead the diamond three from hand. If West wins his king, declarer is almost home. He unblocks diamonds, then draws trumps ending in dummy to cash two more rounds of diamonds and pitch his clubs.

If West can steel himself to duck his diamond king, which would be the best defense today, declarer must still reckon with the possible two club losers. He should cash the club ace and king and lead a third round of clubs.

If the clubs break 3-3, declarer is home free. If the clubs split 4-2, declarer can arrange to ruff his fourth club high in dummy.

Over North’s quantitative sequence, South might accept the slam try by bidding six clubs (a 5-3 fit could easily be best here). However, when he bids six no-trump, he finds himself in an excellent spot; now all he has to do is make it.

After the lead of the spade jack, declarer counts two spades, three hearts and three diamond tricks, which adds up to eight tricks. The key to the deal therefore is that the he needs to take four club tricks, not five; declarer can afford to give up a trick in clubs as insurance to bring home his contract.

This is sometimes referred to as a safety play, though that term is rather misleading. A safety play should be a maneuver to avoid losing an unnecessary trick. Today’s deal is closer to a gambit, where a trick is potentially invested for the greater good of the contract.

In positions like this, if South had weaker club spots, the best play might be to cash the club ace. Here, though, declarer starts by leading a low club to the queen. If it loses, cash the club ace and finesse against East should West shows. This play loses only to a singleton king in East.

However, when the queen holds, do not cash the ace; that fails whenever West has K-10-fourth. Instead, come back to hand with the diamond ace and lead the club nine next, intending to run it if West follows with the six. Of course, if West discards on the second club, you rise with the ace, then finesse against East’s K-10.

At Yokohama last year, this deal pitted Jack Zhao of China against one of his former partners. Zhao, North, reached three no-trump after opening one heart then jumping to three clubs. You can hardly blame Fu Zhong for leading a diamond rather than a club, but that meant 12 tricks for Zhao — a near-top.

However, David Bakhshi and Kazuko Tsumori bid to six spades by North on the deal, and they also received a diamond lead. When Tsumori ran that to her hand, she had 12 tricks … and an even better score.

Six spades by South seems to have too much work to be done on a club lead, but an astute declarer can find his way home even then. Win the club ace, play a low heart to your ace, and trust the defenders’ count signal in hearts. Take just one top spade, then cash two top hearts, pitching clubs from hand. Now ruff a club, go back to the spade king and face the critical decision.

The fall of the spade honors makes it more likely that East holds the spade queen than that West began with precisely Q-J-10 of trumps. It would be right to cash hearts now if East began with a 3=4=4=2 pattern, but if you believe the carding, you should play East for only three hearts. The point is that if you play the fourth heart at once, East can ruff and exit in clubs; instead, ruff the third club and exit with a spade.

In the four-card ending, East must lead diamonds and allow your queen and ace to score.

This board from the quarterfinals of the World Championships in Lyon turned out to be a fine battle between declarer and the defense.

Against four spades, Jacek Pszczola (Pepsi) cashed two top diamonds and wisely did not play a third, as declarer Mikael Rimstedt would have set up his clubs. Instead, he switched to the spade 10. Rimstedt covered this with dummy’s jack, drawing the king and ace. West now held the sole guards in both spades and clubs.

Next, declarer played the king and queen of trump, ruffed his diamond loser with the heart ace and ran the remaining trumps. To retain his club honors, West had to reduce to just one spade. If he kept his spade nine, he would be thrown in with a spade to lead away from the club king. If he discarded his high spade, South’s spade eight would be good. Either way, declarer had his 10 tricks.

After two rounds of diamonds, West needed to switch specifically to the spade queen, so that East would be able to guard the suit with his king.

In the other room, Frederick Nystrom led the diamond ace and, realizing that he would have to open up spades sooner or later, found the necessary switch to a spade intermediate at trick two.

When declarer Joe Grue allowed this to win, West cashed the diamond queen, then played the spade six to the seven and ace. Declarer eventually had to surrender a club and a spade trick for one down, and Sweden had a well-earned game swing.

This was a deal from the quarter-finals at the world championships in Lyon last August. When South declared four spades, West generally led a top diamond.

The New Zealand West then played a second diamond, and the Dutch declarer ruffed and guessed to take the club finesse, a simple and seductive line. But when it lost, a heart back settled his hash immediately for down one.

By contrast, after the same first two tricks, the New Zealand declarer ruffed and led a low spade toward dummy at trick three. West correctly played low — which would have been necessary if his partner had the spade ace rather than the club king. The spade queen won, and declarer played a low spade back to his ace, dropping the king, then took the club finesse and was home against any defense.

A far tougher defense would have been for West to switch to a club at trick two. If declarer finesses, East wins and can switch to a heart. However, declarer can (in theory) riposte by going up with dummy’s club ace and then playing a spade to the ace and a spade.

At yet another table, the Bulgarian West cashed just one top diamond, then led a low heart away from his doubleton king! Declarer won the queen and led a low spade, West taking his king and continuing with a top diamond. Declarer ruffed, cashed dummy’s spade honors and now should have led a club to his 10. Instead, he played a heart to his jack and lost both a club and a heart trick.