How good a contract is six spades here? You may be surprised to know that although the contract looks good, best play will result in only a 90 percent chance.

The instinctive line, however, will fail today. Imagine that you win the opening heart lead, draw trump, and play the club king and a club to the jack. East wins to return a club, and unless you follow an inspired line in the diamond suit, you will lose a trick to the diamond queen.

But you can do much better after the lead of the heart king to the ace. Take the spade ace and king, ruff dummy’s losing heart, then cash the club king and lead a low club, intending to cover West’s card. As the cards lie, when East takes the club eight with the nine, he can do no better than lead a low diamond. When the diamond nine forces the queen, declarer claims the rest.

In this variation, had the diamond nine been covered by the 10, declarer would cash his remaining trumps and discard a diamond from dummy. Then a club to the ace would reveal how that suit lay. If the clubs were 3-3, declarer could claim. If West had four clubs, then the diamond finesse would be a certainty as West could have no more than a singleton diamond. And if East had four clubs and had kept them all he would be down to one diamond, so it would be correct to play a diamond to the king.

In today's six clubs South shook his head reflectively as dummy came down, thinking that he should have been in the grand slam. A few seconds later he was shaken back into wakefulness when he cashed the club king and realized he had an inevitable trump loser.

After winning the opening lead with his diamond ace, he cashed the heart ace and played a club to the king. The heart king and queen followed, allowing declarer to throw both his losing diamonds away. After the spade ace and king both stood up, South advanced the spade eight.

West did the best he could when he discarded a diamond, and declarer ruffed low in dummy. Now came the club queen, and after nine tricks (three spades, three hearts one diamond and two clubs) a four-card ending had been reached, with the lead in dummy. North had four losing red cards, declarer the A-J-9 of clubs and the spade queen. West had three clubs to the 10 and a diamond.

Now declarer led a heart from dummy and ruffed high. To avoid being endplayed in trumps at the next trick West under-ruffed, a defense that would have been good enough had East held the master spade. (South would have led a spade to East, and West would have scored his club 10.) But when declarer led his spade queen, West could score only one of the last three tricks whatever he did.

These days a lot of the swings in high-level bridge come about when you make things difficult for your opponents.

In today’s deal, for example, from the European championships, at many tables East contented himself with a three-club opening, but that did not cause any problems. Either West raised to four clubs and North made a value-showing double which South removed to four spades, or West passed and North bid three spades, which also led to the normal spade game. Where West bid five clubs, some North-Souths settled for collecting 300 and a small loss.

But here West led his singleton spade against five diamonds. Declarer could see that if West had started with three diamonds, then when he got in with the diamond king, he would be able to put his partner in with a club to get a spade ruff, thus defeating the game.

Can you spot his extra chance? Declarer won the spade ace, played a diamond to his ace, and now played the heart ace and king. He continued with the heart nine, discarding his club from hand. West had won an unexpected trick, but he could no longer put his partner on lead to deliver the ruff.

When the teams compared scores at the end of the match, the Finnish pair was pleased to discover that their declarer at the other table had found exactly the same line of play in the same contract. No swing!

Today's deal comes from a correspondent who remarked that the adverse result was fortunately just too small to have cost her side a victory in a knockout match. But the lesson of the deal is interesting, even if the play was not found at the table.

In one room South opened with a weak two spades. West overcalled with two no-trump and North doubled. East removed to three clubs, but that was no real improvement, and eventually went down 500.

South for my correspondent’s team decided to pass, and the auction developed as shown. When four spades was passed around to West, he thought for a considerable time before making his final pass.

West led the heart ace and king, then switched to a club. Declarer lost two spade tricks to go with the top hearts, but he could (and probably should) have succeeded. After winning the club ace, he ruffs a club, ruffs a heart, ruffs another club, then plays off his top diamonds and ruffs a diamond. All he has left in hand are the spade A-Q-10. He exits with the spade queen and sits back and waits to make his ace and 10.

Incidentally, can you see where West went wrong? He should have continued with a third heart at trick three. By doing so, he removes a dummy entry, thus preventing the trump reduction.

In today's deal from the Dyspeptics Club, South, finding himself in his accustomed position as declarer, received a club lead against three no-trump.

He won the first club and tested diamonds, uttering a snort of disgust when the suit failed to break. At this point he gave himself the best chance he could when he cashed his last diamond winner — East carefully discarding spades on both top diamonds — then played hearts from the top. The blockage in the suit meant that he could cash only three tricks there, and the defenders had enough communications to take five winners whatever declarer did next.

As usual, North was dismissive of his partner’s efforts. Can you see why?

It is tempting to be overconfident and expect to take lots of tricks when diamonds come in. But even if diamonds break badly, you may be able to make four heart tricks and your contract; however, you need to test that suit first in case someone has a doubleton jack. As you can see from the lie of the cards today, you have four heart tricks, but you need to retain an entry to the South hand to score the last of them.

Cash the heart ace and queen at once, and when the jack drops doubleton, you unblock the heart 10 and have the entry in the form of the diamond ace to untangle your winners and take your nine tricks.

Not rushing in with a high card was the key to the defense in this hand from the 2002 McConnell Cup Women's teams, where England won the match by knocking out Austria.

A couple of points to note in the bidding: After South had shown a two-suiter with her opening bid, the response of four no-trump asked for the minor. East’s first double suggested defending, and her second was purely for penalties.

Against five clubs doubled Nicola Smith cashed her top two hearts, then accurately switched to a trump. Declarer won in dummy, then played the spade two, on which East, Heather Dhondy, accurately followed low. Dhondy had appreciated that there was no rush to take her spade ace, for even if South had held the king, there were not enough trumps in dummy to cope with the rest of the suit.

South’s queen lost to West’s king and back came a second trump, won by South with the jack. A spade ruff was followed by a low diamond. Again East declined to rise with a top honor, and the eight in the closed hand lost to Smith’s nine. Had East risen in diamonds, she would have had a difficult continuation, and declarer might have ended just two down. As it was, the heart queen return was ruffed in hand, and another spade was ruffed in dummy, but now declarer had to concede two further spades for four down — plus 800 to England.

Playing your delicate spade grand slam, you receive the lead of the heart king to the ace. Before playing to the second trick, you need to identify your 13 tricks. The most likely approach seems to be to set up clubs or to play a crossruff. For the latter you need to take five side-winners and eight trump tricks. In turn, this requires you not to draw all the trump; but can you draw any rounds of trump? That is the question.

Given the weakness of your trump spots in hand, the contract appears to depend on the clubs breaking 4-3 or else you may suffer an overruff. However, there is a slight extra chance which will cost you nothing to take. Before going after clubs, take precisely one round of trump. Cash the spade queen, then play all three top clubs, throwing hearts from hand.

When West shows out but cannot ruff, declarer can crossruff with impunity. If clubs had been 4-3, then declarer would cash the diamond ace and lead a heart. If East discards, declarer ruffs low, ruffs a diamond low, and leads another heart. If East again discards, declarer ruffs and makes the rest on a high crossruff. If East ruffs in when clubs were originally 4-3, then declarer overruffs, draws the last trump with dummy’s jack. Then he ruffs a club, and claims, since dummy’s remaining club is high.