At the world championships in Bali last September, this board was critical in both the women's semifinal match between Netherlands and USA II and also the match between Polish students and Gordon in the Transnational. Both American teams desperately needed a good result, and got one.

The USA women were allowed to make three no-trump when West led the diamond queen and followed with the king, and East did not overtake.

Meanwhile Gordon declared two spades at one table, and defended four spades after the auction shown here, on West’s heart lead. Apparently, after East had pre-empted to three hearts, North-South had had a disagreement about the meaning of South’s double. When Michael Seamon led his singleton heart, declarer won in hand and crossed to a top club to lead the spade jack. Had East made the normal play of ducking, declarer would have been able to complete the drawing of trumps and come to 10 tricks via the club finesse. But Jacek Pszczola covered the spade jack with his queen; declarer could draw a second trump with the 10, but now could not cross back to hand without running into a heart ruff, after which the defenders could set up the hearts and cash out the diamonds, taking a club ruff to boot.

Declarer’s best chance would have been to crash the spade honors to draw three rounds of trumps, but the bad club break would now have held him to nine tricks.

Cezary Balicki of Poland is well known not only for his declarer skills, but also for his astute table presence. Both of those attributes came to the fore on the very first deal from a match in the qualifying stages of last September's Bermuda Bowl in Bali.

After Balicki’s one-heart response, West had shown some interest in the bidding by asking about the meaning of the bid.

The defense against four hearts started with three rounds of clubs, attempting to weaken declarer’s trump holding. Balicki ruffed this in hand and made the first critical move toward reaching 10 tricks by advancing the heart jack. This was covered by the king and ace. Now it would have been very straightforward to draw a second round of trumps, but Balicki suspected the bad trump break. Instead, he cashed the diamond ace and two top spades, then took a spade ruff in the closed hand. West overruffed with the eight and played a fourth club as his final attempt to weaken declarer’s trumps. Balicki found the riposte when he ruffed with the three in dummy and overruffed with the seven in hand. Then he cashed the king and queen of diamonds, discarding both of dummy’s spades, and made the contract via a trump coup when he led another diamond and overruffed West’s heart at trick 12.

For the record, you must not deliberately mislead the opponents. Equally, you must ignore your partner’s mannerisms. But any inference you draw from your opponent’s demeanor is legitimate, if entirely at your own risk.

In the round-robin match from the world championships in Bali last year, this deal proved too much for most declarers.

While the French women had stopped in the small slam, Asli Acar for Turkey played in seven spades. She ruffed the heart lead in hand and cashed all but one of the trumps. That left dummy with two hearts, a club and three diamonds, and West with three diamonds and three clubs. Acar now played ace and another diamond and, after some thought, went up with the king, took a club pitch on the heart ace, then finessed clubs for down one.

Clearly, declarer could have succeeded by taking the diamond finesse. However, even better is to win the heart ace at trick one, pitching the club jack from hand. Now she plays all the trumps and keeps three diamonds and a heart in dummy, facing the diamond A-4 and club A-Q. East will be known to hold the heart guard, so declarer simply cashes the club ace at trick 10, which, as it happens, drops West’s bare king.

But if East had retained the guarded king, she would be known to have come down to a singleton diamond, so now declarer plays the diamond ace, then takes the diamond finesse. If East has the diamond guard and West the club king, the contract fails — but then it was always going to fail. Meanwhile, this line succeeds whenever East has the club king or West has both minor-suit guards.

At the World Championships last September, USA had two teams — the women's open and seniors categories. The experienced USA1 women's squad coasted to a high qualifying position in the round-robin phase of the Venice Cup. On this deal from the early stages of the event, Kerri Sanborn showed that, like Yogi, she is smarter than the average bear.

Her four-spade contract would have been defeated immediately on a diamond lead. However, just as in the other room, East had intervened with a call of three clubs, so West led the club three. Sanborn won the ace and cashed the ace and king of spades to find the bad news.

In the other room, after the top spades the Swedish declarer continued with a heart to the jack, then two more rounds of hearts. West could see the diamond discard coming on the fourth heart, so had no problem in ruffing and returning a low diamond for one down.

Sanborn, however, found a much stronger line. She went after hearts by leading the ace and king, then a low one. It seemed to West that her partner was about to win the queen, so she failed to ruff. The heart jack won the trick in dummy, a club ruff put Sanborn back in hand, and the heart queen was played for a diamond discard. There were now only two diamonds to be lost, and the vulnerable game was home for a big swing to the U.S. team.

At the Senior World Championships in Bali last September, the Scots qualified for the knockout stages in their first-ever world championship appearance. But they came off second best in this deal against Belgium, where Guy Polet was up to the challenge in four spades doubled.

The opening lead was a heart to the jack and ace, ruffed by declarer. Polet next led a diamond to the ace and a club to the queen and king. West then played the queen of diamonds around to South’s king. South now advanced a low club from hand, and West, after some thought, played low, letting East in. He returned the heart 10 to the king in dummy, declarer discarding a club. Declarer had lost two clubs so far, and knew he had one more loser in diamonds. He was faced with the need to pick up spades for no losers.

At this point, declarer had to choose between finding the singleton king of spades with East or the singleton jack with West. Given East’s double of four spades, it was not really a guess at all. Polet led the spade queen from the dummy, and when the jack fell, he was home. He could repeat the finesse against the spade king, draw the last trump, then give up a diamond. The diamond 10 was the game-going trick.

Exciting stuff — particularly when you learn that in the other room the hand was passed out! Just for the record, Scotland won the match anyway, despite the loss here.

This week's deals all come from the 2013 world championships in Bali, held exactly a year ago. Linda Cartner of the New Zealand Women's team had to defend perfectly to defeat the Indonesian women's contract of five hearts doubled in this deal from their round-robin match.

Glenis Palmer’s two-spade opening was weak, showing five spades and a four-card or longer minor, and Indonesia’s Lusje Bojoh had something to spare for her overcall of four hearts. Not surprisingly, when Cartner competed in four spades, Bojoh took the push to five hearts, promptly doubled by Cartner. The lead was the spade king, and declarer ruffed and took six rounds of hearts. In the six-card ending, Cartner came down to her master spade, both her diamond honors, and king-third of clubs. Meanwhile, dummy kept three clubs, a diamond and two spades. Declarer next played the club queen, and Cartner found the killing defense of ducking. If she wins, declarer can get to dummy’s long club and loses only one trick in each minor. Bojoh continued with ace and a third club, but Cartner could win and play the spade ace. Declarer had to ruff and lead away from the diamond king for one down, plus 100 to New Zealand.

Cartner had to come down to these exact six cards in the ending. If she throws a second club, she can no longer duck the club queen, while if she keeps three diamonds and no spade, she will have to lead diamonds for declarer after winning the third club.

Today's deal seems to be a simple enough declarer-play problem, but there are hidden depths that make the problem more challenging than it first appears.

South has no good way to make a slam-try below the level of game. Doubling, then jumping to four spades, sounds like a moose. However, North has no reason to contemplate moving beyond game, which is just as well today.

When dummy comes down on the lead of the heart queen, South should assume that he has 10 tricks unless trumps do not break, but he needs to plan what to do in case of bad splits. He wins the heart ace, then plays the spade ace andking to reveal the bad news. Now the secret is to find a way to turn the unpromising prospects in the North or South hand into an extra trick.

First South cashes one top club (in case East has Q-J-third of clubs and forgets to drop an honor), then plays a diamond. West wins the ace and exits with a second top heart. Declarer must win and continue with the club king, followed by the club three. When East wins, he can do no better than force South with his remaining club winner. After ruffing the fourth club, South plays his remaining top spade and another spade to endplay East. That player has only diamonds left, and so declarer’s heart loser disappears on dummy’s diamond king.

The White House Junior International is held every spring, attracting players from all around the world. Four years ago almost 150 juniors, including those from as far afield as Australia, Japan and the USA, arrived in Amsterdam for the event. Juniors tend to bid the spots off the cards, so for example the semifinals saw three of the four teams arrive in six hearts. All the declarers were successful, so their card-play proved that their confidence was not misplaced.

The bidding at one table was as shown in the diagram. West led the club ace, then switched to a low spade. Not surprisingly, the spade jack held the lead. How should South try to bring home 12 tricks now? Declarer had to negotiate trumps, but while that would be necessary, it would not be sufficient. South worked out what he needed when he played off the heart ace and took a successful trump finesse. The heart king drew the last defensive trump, then another spade finesse was followed by the spade ace for a diamond discard. Dummy’s remaining heart was overtaken in hand and the last heart cashed, West discarding a diamond and a club. But finally the club king squeezed West in diamonds and spades and the slam came home.

The key to the hand was the trump finesse. For the slam to succeed, West needed to hold at least three diamonds, and so be susceptible to a squeeze — which in turn implied he could be assumed to have short hearts.

Arguably, it is easier to learn from other people's mistakes than from your own. Have a look at what happened here to South; but before you criticize him, consider whether you are entitled to cast the first stone.

At the table South did not compete to three spades, refusing to be pushed just because of his decent spades. But when his partner doubled, announcing the balance of power, he wisely decided not to defend, and found himself in game a moment later.

So far so good. But after the lead of a heart to the ace, East continued with the heart queen which declarer covered and West ruffed. When the club shift came and both minor-suit finesses failed, South was down one. He could feel justifiably aggrieved at the bad luck he had run into in all three of the side-suits.

South was undeniably unlucky. But he had the fate of the contract in his own hands.

All declarer had to do was duck the second heart rather than cover the queen. The spot-card led had made the 7-1 break somewhat more likely than usual, after all. West would not be able to afford to ruff the trick or declarer has a home for dummy’s club loser, so he discards a club. The next heart is ruffed and overruffed. But now South simply draws trump and passes the diamond jack, not caring if it loses since he now has a home for dummy’s club loser on the fourth diamond.