Today’s deal saw South declare six spades after North had upgraded his hand to a balanced 18-19 count by virtue of his great controls. When North showed his spade support, South cuebid his heart ace, North subsequently continuing his optimistic approach by using keycard and driving to slam.

West led the club 10, and it looked logical for South to try to set up hearts, planning to come to nine tricks in the majors and three tricks in the minors. The first order of business was to win the opening lead with the ace, and lead a trump to the king. Now he unblocked the heart ace, cashed the spade queen, then drew the last trump by crossing to the spade ace.

Then came the heart king-queen, throwing two clubs from hand. Had hearts broken, South would have ruffed out the hearts and given up just one diamond trick. When the hearts failed to break, with West long in hearts, and thus potentially short in diamonds, declarer led a low diamond from the table without cashing the ace. East ducked his diamond king smoothly, and South’s diamond queen won the trick.

Now South crossed back to dummy with the diamond ace and led a second diamond back towards his jack for his 12th trick.

Had East been long in hearts, it would probably have been right to ruff a heart to hand and pass the diamond queen. That line guards against East being short in diamonds with either the singleton or doubleton 10 or nine.

Today’s deal comes from Larry Cohen’s latest book: “Larry Cohen Teaches Declarer Play at No-trump”.

In three no-trump, on the lead of the diamond five, we don’t know whether diamonds are four-four. Let’s say RHO plays the diamond queen and we duck. There is no rush to take the diamond ace even if the hold-up doesn’t seem to serve a very useful purpose.

When East returns the diamond 10, we win with the ace, West contributing the diamond four (an honest card that helps you more than it helps East). Now what? Today, diamonds don’t appear to be four-four; if they were, West would have led the diamond four at trick one. It looks as if West started with five and East with three. If that is so, playing clubs will lead to instant defeat. The defense will win the club ace and run the diamond tricks.

Instead, we should take our only chance, which consists of playing on hearts. Of course, with only seven hearts between the two hands, the odds favor finessing as opposed to playing for the drop in hearts.

If the queen is onside, you will come to nine tricks. Admittedly, if the finesse loses, you will fail by two tricks, but taking the only chance is better than giving up.

By contrast on the initial lead of the diamond two, promising a four-card suit, you would win, and drive out the club ace. You would expect the defenders to be able to score three diamonds and an ace, but no more.

The South hand is in no way good enough for a two no-trump opener, which should be 20-21. Only rarely will you consider upgrading a 19-count. Your plan of campaign should be to open one heart, planning to raise a response of one no-trump to two, to suggest precisely these values. At the table, when partner raises to two hearts (a constructive call if you play the forcing no-trump) you can offer a choice of games with a call of three no-trump. Now, assuming North decides his small doubleton club is a danger signal, you should finish up in four hearts rather than three no-trump.

After a spade lead, there is a slight risk of a diamond or spade ruff, but South might well decide that this looks like a sensible moment for a safety play in hearts if the diamond finesse works. So it feels right to win the spade lead and play a diamond to the jack.

If the finesse loses, you will play a heart to the ace and a heart to the jack. However, when the diamond finesse wins, you can afford one heart loser but not two. So lead out the heart king, then play a low heart to the nine.

If you lose this trick, you surely have the rest bar the two club losers. If West has four hearts, you have held your losers to one. And what if East has four hearts? Then when West discards on the second round of hearts, go up with the ace and complete the drawing of trump.

Against your six club contract West leads the diamond 10 to East’s ace, and East returns a diamond to your king. You can try the heart finesse for the 12th trick. Is there anything better?

There is indeed; you must make the most use of your discard coming on the diamonds. Best at trick three is to cash two of your high trumps from hand. Then, cross to the trump honor in dummy, cash the heart king and ace, and discard your losing heart on dummy’s diamond queen. Finally, ruff a heart in hand and lead a spade to the board to discard your spade loser on the established hearts.

This line of play is a real improvement on the straightforward heart finesse. It negotiates all the 3-2 heart splits, and also succeeds when the queen is singleton.

This is considerably better than the straightforward heart finesse, which is only a 50 percent chance, plus the slight chance of a singleton queen offside.

On average, a suit will break 3-2 about two thirds of the time, and when there is a singleton queen that ups the odds for this line even further.

Incidentally, you will note that had the defenders shifted to a spade at trick two, that removes dummy’s late entry. Declarer must lead out two high trumps from hand then cash the two top hearts, take his discard, ruff a heart high, and go back to the club king to obtain his discards.

Sometimes declarer needs to find a way to entice a defender to continue with the suit that has been initially led, rather than make a potentially damaging shift. Declarer found a neat solution to just that problem in today’s deal.

After North raised his partner’s two no-trump opening to three, West was aware that since North-South had not tried to locate a major suit fit, it might well be right to attack in a major rather than a minor. But West was unimpressed with the quality of his major suits, and had a natural sequence to attack from, so he chose the club jack for his opening salvo.

South immediately saw he would need four tricks from clubs to make his game. That would be easy to do, if the suit broke 3-2, but declarer thought that this was relatively unlikely to be so. After all, why would West be leading from a three-card suit, as he must have at least one four-carder available?

South realized that if he cleared the clubs, East would surely show where his values lay. Now West would be likely to find the diamond switch, after which South rated to lose at least four tricks in that suit.

So at trick one South dropped the seven under the jack. West, seeing his partner’s eight, and noting that neither the four nor the three had put in an appearance, took the eight as encouraging, and played a second club. Declarer wrapped up his contract, unsuccessfully trying to conceal a smirk as he did so.

An avoidance play relates to a position where it is important to keep one particular opponent off lead — because they have winners to cash, or can make a killing shift, while the other hand poses no such threat.

Here you play three no-trump rather than four hearts, when North sensibly eschews the 5-3 heart fit. On the lead of the club three, East plays the jack, and you duck. Now East plays a second club; should you win or duck again?

It is best to win; now to find a ninth trick you must set up hearts without letting West in; which means you need the king to be onside. If East has three hearts you can afford to finesse, then play ace and another heart. But what if he has the doubleton king? Then West would win the third heart.

To cater to both chances, cross to dummy and lead a low heart. If East plays the king, duck; if he plays low, finesse, then go back to dummy to repeat the exercise. If he plays low, rise with the ace; if he plays the king, you duck.

Do you see a counter to declarer’s play if he ducks the second club? On the third club East should dramatically discard the heart king. That way, declarer cannot establish hearts without letting West in.

This is why South should win the second club before embarking on the avoidance play. If East turns up with a third club, the suit is splitting 4-3 and the defense cannot take more than three club tricks.

20 years ago this charming deal cropped up in the Cavendish Teams. I have not seen a position since then, with three such different possibilities from the diamond suit.

You declare six spades, and receive the lead of a top heart. You win the ace, ruff a heart, draw trump in three rounds, and now have to tackle the diamonds.

When you lead a diamond towards the dummy you plan to insert the queen if West follows. If it holds, you have a sure-trick line available: you cross back to hand, to lead a diamond to dummy’s nine.

So what happens if West follows to the first diamond, and the queen loses to the king? Then you regain the lead and play off three rounds of clubs, ruffing the third in hand, and run the trumps to squeeze East in the minors should the diamonds do not split.

The actual lie of the cards is more interesting. When West shows out, East is marked with eight cards in spades and diamonds. You cannot make the contract if he has three hearts so you should play West to guard the fourth round of clubs.

The winning line is elegant: win the diamond ace, play off three rounds of clubs, and ruff in hand, then run the trumps to reduce to a three-card ending, after two rounds of hearts, three clubs and five rounds of spades.

In this position North, East and South will all have three diamonds left. Now a diamond to the queen forces East to win, and lead up to the diamond nine.

This month I have been running deals from Larry Cohen’s recent book: “Larry Cohen Teaches Declarer Play at Notrump”. So let me run a deal which shows him as the hero, in a no-trump contract.

In the 2000 world championships, Larry as South played one no-trump on the lead of the heart 10 to East’s ace. At trick two, the heart queen was returned. How should South play?

Larry counted five sure tricks, and could develop two more from either minor. However, whichever suit he worked on, declarer would have to knock out both the ace and king. So what is the potential problem?

Every suit is at least double-stopped, but the defense is threatening to take seven tricks (the minor suit ace-kings and three heart tricks) before declarer can come to his seven. Look what would happen if South won the heart king at trick two and went to work on one of the minors. Whichever minor he tackled, West could win and play a third round of hearts, establishing his suit. He would still have an entry, and declarer would lose the race.

Once you identify the problem, the solution is not hard. You must allow East to win his heart queen at trick two. In the unlikely event that he produces a third heart, the suit will be four-three and there is nothing to worry about.

Equally, even if East shifts to spades, declarer has plenty of time to set up his seven tricks by playing on one minor or the other.

South does not have quite enough to invite game with a jump to two spades, but when North raises, showing significant extra values, South can go on to four spades.

If you just looked at the North and South cards here, you would think that four spades ought to present no problems. However, let’s look at the auction, before giving in to premature euphoria. West has opened one heart and when he leads the king, his partner follows with the 10. Using regular signals, that suggests East possesses at most a doubleton. Accordingly, when the defenders play three rounds of hearts declarer is in grave danger of running into an over-ruff. And it will not be sufficient simply to ruff high on this trick. That is merely the start of the delicate path declarer must tread.

At trick three South must ruff high in dummy with the spade queen. After that he needs to play West for the doubleton spade ace. So he leads a club to the queen, followed by a spade up.

In this position what is West to do? One possibility is for him to play the ace of spades and play a fourth heart – a defense that would be successful if East began with the doubleton spade jack, though not today. But it does West no better to duck. If he does, the spade king scores, after which declarer must duck a trump. When the spade ace pops up, the defenders can no longer promote a trump trick for themselves.