It is a cliché (and not an especially accurate one) that rules are made to be broken. What is more to the point is knowing when to apply a rule and when external events should persuade you to vary from a principle.

Today’s deal comes from last Summer’s Nationals in Washington. Everyone knows that missing four cards to an honor, it is right to play for the drop. This is based on the phrase ‘Eight ever, nine never’. But this statement about what to do when missing four trumps is only true in a vacuum. The concept is based on the vacant space principle, which gives you very slight odds of playing for the drop. However, when you get a count of a side suit, it may affect your decision one way or the other, and this hand exemplifies that theme.

When the field played four spades by South, West obediently led a diamond, in response to his partner’s overcall. This would have been a splendid moment to find the false-card of leading the five, but in real life everyone would lead the six, top of a doubleton. East cashed his three red-suit winners, and led a third diamond.

Without the clues from the auction the way forward for declarer would not be clear. As it is, though, the auction strongly suggests that declarer should ruff high, cash the other high spade and play a spade to the 10. This is because the 6-2 diamond break makes West rather more likely to have three trumps than two.

In today’s deal from a matchpoint pairs event South’s three diamond call was natural and forcing, and asked North to raise spades if he could. Having found the spade fit, South was able to show his heart void in response to the key-cards ask. After hearing the response, North assumed diamonds would run, and gambled on locating a 13th. And yes, it would have been wiser today to bid the grand slam in diamonds, where 13 tricks would have been easy.

While a club lead would have worked well for the defense, at trick one there was no reason for West to work that out. South could count 12 tricks, and appreciated that East was likely to hold both the heart ace and club king; but the menaces for a squeeze did not seem well-placed.

Still, all declarer could do was run his winners and hope for the best. After ruffing the opening lead South drew trump, then played a fourth round, discarding the club two from dummy. Now came the diamonds, and when the last diamond was played, East was caught in a dilemma.

If he threw the club 10, dummy’s club ace would be cashed and a heart ruff would allow the established club queen to score. Alternatively, the heart 10 discard would permit a heart ruff to establish the king, with the club ace as the means of access.

This position is called a trump squeeze, and it is the see-saw element of such positions that makes it especially attractive, I think.

On this hand from the 1995 World Junior Championships the two instructive themes are firstly to try to cherish your partner, and secondly that you may be able to protect him from the consequences of his error, if you do not allow emotion to get in the way.

When West led the club eight, (third highest from three or four cards) Andrew Moss as East won his queen and had to decide what to do next.

He saw that if the defense could play three rounds of spades it would promote a trump trick for the defense. So Moss switched to the spade queen; when he followed up with the spade king, he made it easy for his partner to work out to overtake and play a third spade.

Arguably, this is no more than routine good technique. But what if (as happened at some tables) your partner, having overdone the Sunday lunch, supinely plays low on the second spade?

As East you know declarer has all the top red-suit cards, and that he cannot ruff any spades in dummy. Since you can see at least two club tricks for him, declarer must have a 4-5-2-2 shape for the play so far to make any sense. Switch back to a club now, to break up a squeeze on your partner in the black suits.

If you play back a diamond for example, declarer takes his seven red suit winners and the last trump forces your partner to concede. By breaking up a squeeze on your partner, you should earn plenty of Brownie points.

One of the arts in defense is to know when to be an optimist. If you need partner to have a specific card to beat a hand, then assume he has it and defend accordingly.

Here, when West led the heart three against three no-trump, East won his king and returned the heart 10 to dummy’s ace. South continued with a low club from dummy. East let declarer win in hand and South now switched horses by leading a diamond to the king and ace. At this point, the defense could do nothing to defeat South’s game.

However, at trick one East should have worked harder on his addition and subtraction. Since he and dummy hold 24 HCP between them, and South has admitted to at least 15 HCP, that leaves West with at most one point. To have any chance to set the game East must assume this is the heart jack.

Since East can see his partner has no more than five hearts, and that he needs to maintain communication with partner within the heart suit, East must follow with the 10, breaking a cardinal rule and finessing against partner.

Unless declarer has superhuman powers he will win his queen, and go after a minor. East should rush up with his ace and complete the unblock in hearts by returning his king to dummy’s ace. East will take his remaining ace at soon as he can, and revert to hearts to set the game.

And if declarer ducks his heart queen at trick one? Then find an easier game to play in.

Today’s deal demonstrates how to have your cake and eat it too. When playing teams you want to ensure making your contract if you can, or defeating it if humanly possible. Overtricks and undertricks are the lifeblood of the pairs game, but basically irrelevant at teams.

So let’s look at a pairs deal, where you declare four hearts on the defense of three rounds of spades, ruffed in hand. Your target is to make as many tricks as possible, while not going down if you can avoid it.

If you play hearts from the top and find the 4-1 break, there is nothing you can do to recover, against competent defense. West will ruff the third round of clubs, then exit with the heart jack, if declarer has drawn only two rounds of trump, or exit in spades if declarer drew three rounds of trump.

So what can declarer do to sidestep this outcome? You could play ace and a low heart, giving up a trump trick to settle for 10 winners. But if hearts break, you would then have sacrificed a trick for nothing.

A better line, which combines safety with excellent chances for 11 winners, is to cash one heart, then cross to dummy with a club to lead a second round of trump. When East discards, you put in the 10, and can claim the rest after West wins the jack. If East follows to the second trump, win the king, and unless West shows out, you have the rest. If West discards, try to cross to a top club to finesse in trumps.

My wife Judy was previously married to the late Norman Kay, one of the strongest players never to win a world title. He declared this deal, from the semifinals of the 1968 Olympiad.

Norman was always a deliberate player, and when West led the spade jack, he took considerable time before committing himself. Eventually he won, tested the hearts and, when they broke 3-3, took the diamond finesse for an overtrick.

Was his line of play the best? It fails had hearts divided 4-2 with the diamond finesse wrong. As against that, playing on diamonds first might work if that suit divided evenly. But if the diamond ace is followed by a diamond to the queen, which is allowed to win, does declarer now risk a third diamond, or does he try the hearts?

Once you have identified the problem, maybe you can spot the best play for declarer. This would have been to try a low diamond towards the queen before releasing the ace. If the queen wins, you are still in control in the diamond suit and can even cope with a bad heart break by coming to hand in spades and leading a low heart to the 10. This loses only to the bare heart jack in East. And of course if the diamond queen loses to the king, there is still time to test both red suits.

So were the US lucky here? Not exactly; in the other room the Dutch declarer was in seven no-trump — which simply needed both hearts 3-3 and the diamond finesse to work.

Wash your mouth out with soap and water if you even thought of opening today’s North hand one no-trump. After North opens one diamond and jumps to three diamonds, South has to decide between passing and trying for the no-trump game. He has only an eight-count, but the diamond jack may be useful in establishing the diamonds. It seems right to me to take a shot at three no-trump.

Now let’s switch to the defenders; as West, would you consider leading the club queen? It is certainly the right suit to lead, but the queen is unquestionably the wrong card. The most likely way to beat the hand is by finding partner with a top honor in clubs, but if that is so, it must be right to lead a small club. It may be necessary to unblock the suit in several scenarios, for example if partner has the doubleton ace, king or 10 of clubs.

OK, let’s switch back to declarer’s seat. When West leads a small club, which club should you play from dummy at trick one?

If the clubs are 4-3, your play will be irrelevant; but the clubs pose no danger, since there are only three tricks for the defenders to cash. If the clubs are 5-2 with East having a significant doubleton honor, you must play the ace to block the clubs. Try it out — and you will see that it works. You win the ace, drive out the diamond ace, and the defenders cannot run clubs whether East unblocked his club king at trick one or not.

In today’s deal South could not bear to conceal his five-card major at his first turn. West’s cuebid of two hearts showed 5-5 in spades and a minor, and now South tried to make up for lost time by rebidding three no-trump at his next turn. North read him as having a far stronger hand than this and leapt to six hearts, a contract that would have been easy had South held a doubleton in diamonds rather than spades. As it was, though, slam was very tricky to play after a spade lead, since the diamond king was surely going to be offside. Can you spot declarer’s best chance?

Declarer should win the spade lead and draw only two rounds of trump with the ace and queen. Then he must rely on four rounds of clubs standing up – almost a given, since the two-suited overcall means West can hardly hold more than two clubs. After pitching a spade on the fourth club, South can ruff a spade to hand, draw the last trump with the heart king, and reduce to a four-card ending where he has three diamonds and a trump in each hand.

Now he can lead the diamond nine from dummy, planning to let it run to West to endplay that player. If East holds one of the jack or 10 of diamonds, he will be at liberty to cover the nine, but South can play the queen. Though West can win the king, he must next lead back a diamond, and dummy’s eight will win the trick.