At the 2016 junior world championships held in Salsomaggiore, this deal occurred during the quarter-final match between the Sweden and Norway juniors.

Mikael and Ola Rimstedt, who are rapidly making their way to becoming one of the world’s top young pairs, bid this hand to three no-trump. The one diamond opener was natural and unbalanced, the two no-trump call showed extras with long diamonds, the three diamond call suggested a minimum hand with only four hearts.

Against three no-trump, Christian Bakke led a low spade; this went to the eight, jack and ace. Now declarer led a spade to the 10, and took a losing diamond finesse, East’s two being upside down count.

When Bakke won this, he decided declarer rated to be 3-6 in spades and diamonds. Obviously the defenders needed to run hearts now, and the question was whether to play partner either for ace-queen-third of hearts (when a low heart would let the defenders cash out easily); or queen-nine-third of hearts and the club ace — in which case again a low heart was necessary. But if declarer had a singleton honor, the heart king was necessary, since it catered for the stiff heart queen.

Bakke decided that with eight hearts and six clubs visible in the two hands, declarer rated to have a singleton heart more often than a doubleton, so he shifted to the heart king to defeat the game. This was worth a 10 IMP pick-up when three no-trump came home in the other room.

Today’s deal cropped up during the first session of the girls’ semifinals at the junior championships in Salsomaggiore last year.

Before I tell you what happened at our featured table, consider the play in five diamonds here. At every table where diamonds were trumps, the defenders led spades. East either tried to cash her top spades, or won the spade king to shift to a club.

After this start, it was easy for declarer to infer that, given East’s opening bid, West must hold the diamond king. This allowed declarer to drop the diamond king offside. In the semifinal between Australia and Indonesia, Renee Cooper followed this line in five diamonds, and could set up hearts to pitch the club loser, making 12 tricks.

At her counterpart’s table Kirstyn Fuller from Australia was East, but here the stakes were higher, since she was defending six diamonds. She deceptively won the opening lead with the spade ace and shifted to her club nine.

Now declarer assumed West had the spade king, so the diamond finesse rated to be working. She took the club ace, crossed to a heart, and finessed in trumps. When West won with her king, she could cash her club winner and give her partner a club ruff. That meant three down – but had Fuller not made the right play to trick one, the slam would surely have come home; so the false card generated a swing of 22 IMPs.

Australia went on to reach the final, where they lost to a strong Dutch team.

Today’s deal represents a slight variation of a hand that came up in the quarterfinals of the junior world championships. The Polish team who were spearheaded by Michal Klukowski and Justyna Zmuda won the junior title. (They have been playing regularly for the open and women’s teams respectively, for the last few years). This deal resulted in a big swing for their team.

To focus on the problem look just at the auction, together with the West and North cards. You lead a heart against six diamonds, won in dummy. Declarer now plays the diamond king, which goes to the nine and declarer’s six. Plan the defense. When you have decided, look at the full deal.

If you duck the first trump, what should declarer do? He has two sensible approaches: one is to take the diamond nine at face value and play to ruff out clubs – which would be necessary if both minors break badly. But if declarer does that, then if the cards lie as in the diagram East ruffs the second club, and defeats the slam. If you win the diamond ace, declarer cannot go wrong.

(For the record: in real life the diamond nine was singleton with East holding 4-7-1-1 shape. When the diamond nine appeared, West ducked, and declarer correctly went after clubs at trick three, successfully ruffing out the suit. Had he played a second trump himself, the defense would have played a third trump and forced declarer to guess clubs.)

In today’s deal six spades would have been an excellent contract had North held the spade 10, so that South could maneuver a club ruff without risk, or if the opponents had not bid clubs, so that the chance of an over-ruff in clubs was not almost guaranteed.

At the table South won the club lead and gave up on trying to ruff a club, since even if West had only two spades and South drew two rounds before giving up a club, East could play a third spade himself; and if West had the outstanding trump this line would lead to immediate defeat.

Instead declarer drew all the trumps at once, and was pleased to see East following three times. That marked him with 10 black cards and made it almost a sure thing that West would have sole control of the red suits.

Next South cashed the diamond queen, king and ace, throwing a club from his hand. Then came the key move of leading the losing club to East, to rectify the count.

East took the trick and exited in hearts. South won the heart king, cashed the two remaining top spades, and in the process reduced the hand to a two-card ending. As the last trump was led, dummy had the doubleton heart ace and a diamond, and West was forced to discard his diamond winner or come down to only one heart. When he opted for the latter, South pitched the diamond from dummy and scored trick 13 with the heart seven.

When China played Brazil on view-graph in the early stages of the 1995 Bermuda Bowl, a huge swing hinged on the defense to an ambitious slam contract. China had played game in the other room, but Mello, sitting South for Brazil, took a shot at slam here.

West, had a choice of three side suits to lead; from the perspective of good journalism, he was faced with a “Goldilocks” problem. The club jack would have been too tough for declarer, the heart seven would have made life too easy, and his actual choice of the diamond six was “just right”.

Mello ruffed the diamond ace, drew trump pitching a diamond from dummy, and finessed the heart jack. When East won the heart queen he returned a passive diamond, allowing declarer to ruff, cash the heart ace and run all the trumps. In the four-card ending dummy kept two hearts, one diamond and a club. West came down to a diamond and three clubs, but had to discard a club (to keep his diamond king) when declarer played a heart to dummy.

Since East had already been forced down to two clubs to keep the hearts guarded, declarer could finesse the club queen, cash the ace and take trick 13 with the club seven.

The defense could have broken up the position by attacking the pivot suit, here clubs. If East had switched to a club, then dummy would have had to let go of its club in the ending, and the communications would have been destroyed for the double squeeze.

South has enough to try for game, but not to bid it on his own, when North raises hearts. His three club call focuses on needing help in that suit. When North shows diamond values, South bids the game. While it might be right for North to use the three diamond call as ‘last train’ — meaning a buck-passing device — the result would be the same.

Consider how declarer should play four hearts on the defense of three rounds of spades, as East pitches a club. He ruffs and … what next?

It looks natural to cross to the diamond ace and finesse in clubs. But when West wins and leads a fourth spade, forcing South to ruff, East gets to pitch two clubs on the third and fourth spades, and is now out of clubs. If South tries to cash the club ace, East will ruff. If South draws trumps, he will lose a second club trick. So from this point on the contract can no longer be made.

South’s interior clubs are a mirage; the hand would be easier to play if South had the ace and three small clubs in hand. The simplest way to ensure 10 tricks is to play ace and another club. Having given up a club, and ruff two clubs with dummy’s high trumps. For the record: South should cash his high diamonds before starting the cross-ruff. This prevents the opponents discarding their diamonds during the cross-ruff.

And finally, the defenders would have done best to shift to trumps at trick three to prevent the cross-ruff.

Today’s deal is not especially challenging, but it does require a little care and attention. Against four spades the club king is led and ruffed. Declarer appears to be in decent shape so long as diamonds behave, but when declarer cashes the spade ace, and discovers the 4-0 trump break, he needs to be a little careful.

If he plays diamonds from hand by leading ace and another diamond, and finds West with a singleton, he might lose three diamonds and a heart. So he does much better to cross to the spade jack at trick three and finesse in diamonds, which is the best safety play against a 4-1 diamond break.

The diamond finesse loses, so declarer ruffs the next club and plays the diamond ace and another diamond. West wins and can play a third club if he wants, but declarer counters by discarding the heart four from hand. Now dummy’s spade six can take care of the next club, and declarer can cross to hand in hearts and draw trump to score his long diamond at trick 13.

Note that if declarer draws trumps at once, he runs out of trumps. Incidentally, had spades broken three-one, declarer would have cashed a second trump from hand and played the diamond ace, then crossed to dummy with the spade jack to lead a diamond towards his queen. This protects against all the four-one diamond breaks except those where West began with K-J-10-x, in which case there is nothing to be done anyway (without the sight of all four hands).

Do not worry about how to bid the South cards. The chances are that you’ll get a hand of this strength about once every 10 years (so long as you play two sessions of bridge a day, every day of the week).

South receives negative responses from North at his first three turns, as well he might. He then has to decide whether to risk the five-level in search of a slam. When he does, North has – in context – a pretty good hand with a guaranteed working honor and three trumps, enough to bid on.

To make his slam, South must try to avoid the loss of two spade tricks, which is simple enough if each opponent has three spades. If spades break four-two, however, South must play with some care. The key is to draw only one round of trumps before conceding a spade. At that point the defenders rate to exit in a minor, and now declarer draws a second round of trump and tests spades.

South must hope that the player with four spades also has three or more trumps. Then South will be able to ruff his last spade in dummy without being over-ruffed.

The traps are to draw two rounds of trumps before giving up a spade, when East would return a third trump to kill the spade ruff in dummy. But also note that if South does not draw two rounds of trump, instead cashing one or two top spades before giving up a spade, then East can lead another spade and allow West to ruff. Either way, South would go down.

It is almost always right to reopen the bidding when dealer opens and the auction dies on the first round. If the opponents belonged in game, they would surely not have stopped at the one level. The hand almost surely belongs to you, or the limit of the deal is a partscore for the opponents.

In any event, South has plenty in hand for his reopening action today. When North shows a high card raise of spades, South bids game. He may not make it, but he might as well bid it and find out the hard way.

After leading a top heart, West shifts to the club queen. Now South is threatened with the loss of a heart, a club, and two diamonds. What can be done to avoid that?

Declarer must try to establish one of dummy’s hearts as the 10th trick; but it will need a little defensive assistance. Declarer ducks the club queen, and now to set the game East must overtake and shift to diamonds. When, instead, he encourages on the queen, South wins the next club and ruffs a club. Then he draws trump ending in dummy, and leads the heart 10, throwing away a sure loser in diamonds.

West can win, but is endplayed. He does best to lead a low heart, forcing declarer to guess whether to put up the nine. South should do so: not only might East have acted with as few as four or five points, he would surely have covered the heart 10 on the second round, to set the game.