It's clear that you need at least two tricks between clubs and hearts outside of the SA to defeat this contract. In other words, partner needs either the ♥Q or the ♣AQ if he does not have the ♥Q. If you play the ♥K and it loses to the ace, as it surely will, and a spade is led driving out your ace, which suit are you going to return?   The way to avoid the guess is to play the ♥J at trick one!  Partner is not underleading the ♥A into the strong hand so declarer has that card.  If the ♥J loses to the ace, you will know it is right to continue with hearts when in with the ♠A.  If the ♥J loses to the queen, you will know it is right to switch to a club. Third hand high does have some exceptions, you know.

 Unless East has an honour in hearts it will be immaterial which heart West chooses to lead.  However, if East happens to have the jack, the queen will be the superior lead fror three reasons.  First, declarer may misjudge the lie of the suit.  Secondly, the presence of the nine in West's hand means that declarer's options in the suit will be restricted.  Finally, if declarer does go wrong the effect will be to create a vital entry in East's hand.  This last consideration is of prime importance, since in this type of hand West is all too likely to find himself repeatedly on play.

In this example, declarer wins the ♥Q lead, crosses to dummy with a spade and finesses a club to West's queen.  A second heartis won by East.  Appreciating that his own hand is now dead, East switches to a diamond and now the contract is doomed.  

If West had started with a low heart, East will never gain the lead and declarer is likely to bring home the contract without ever being seriously threatened.

The tip from the last 2 day's hands is that instead of always pushing out an unimaginative small card from 3 or 4 to an honour, you should consider whether to lead the honour.

It is normal to lead small from a suit of 3 or more cards headed by an unsupported honour.  There are however some basic situations where the lead of a high card may produce better results.  In a competitive situation, a defender on lead with Kxxx of his partner's suit and few other assets may well start with the K in order to retain the lead and find the killing switch through dummy.  

Today's hand requires a little more thought.  The opponents bidding suggests that they have little to spare.  Furthermore, South is unenthusiastic about North's spades.  For that reason it is good play to attack with a spade,  No other lead appeals and declarer may be embarrassed by an early attack on dummy's entry.  Having reached that conclusion, the best card to lead is the King.

Declarer may misjudge the lie of the suit - or the King may win a trick by force.

Look at the full deal.  Declarer naturally ducked the opening lead and received a nasty shock when at the next trick, the Jack of Spades loast to the Queen.  He elected to discard a heart.  Then a heart switch and continuation held declarer to 6 tricks.  At the other table, after a heart lead, declarer scrambled home with 2 hearts, 2 diamonds, 4 clubs and a spade.

South figures to have five spades (probably would not have passed 4♠ knowing of a 4-3 fit) and has one club leaving South with 7 red cards.  If South has four diamonds and three hearts, partner has a singleton diamond and might have led it in desperation. Most players like to lead singletons so much that they lead one even if they don't have one. No, it looks more like South has three diamonds and four hearts. If that is the case, partner has a doubleton heart and you can give partner a heart ruff if you shift to a heart and play a heart each time you get the lead in spades.

If declarer holds ♦Q there is no hope of beating the contract, so assume partner holds this card and discard the ♦K at trick 2 to create an entry for partner's spades.  If you found this defence at the table then you could look forward to seeing your name in the local paper.  The contract is however unbeatable.  All declarer has to do is win the first trick and play a diamond.  If you follow small he rises with the Ace and ducks a diamond. If you rise with the King, declarer ducks the trick.  The moral of the hand is that there is no point in holding up when you can read the lead as a singleton.  To do so merely gives a defender the chance for a spectacular discard.

The first thing to appreciate is that playing on clubs will inevitably lead to the loss of 2 clubs and at least 3 heart tricks.  Clearly diamonds must be your source of tricks.  There will be no problem if the suit breaks 3-2. If the suit is 4-1, you can succeed whenever West holds 4 cards and East has the singleton 8 or 9.

The ♥K is the only side entry to dummy, so win the first trick in hand with the ace. Then lead the ♦10. When this is covered with the jack, win with dummy's king and play the 3 to your 7, East follows first with the ♦8 and then shows out.

West has no answer: If he takes this trick, you will be able to finesse the ♦6 on the next round of the suit. If West plays low, you continue with a diamond to the ace and another diamond to set up a long diamond, with the ♥K as the entry to cash it. Of course, if West had not covered the ♦10, you would have played low from the dummy and won the trick. Then, the A, K and another diamond would have set up a long diamond, again with the ♥K as the entry.

Given the bidding and lead, you can be certain that West holds the ♠A.  In that case, success is assured.  Duck the ♦10 in both hands.  Win the next trick, draw trumps and ruff a small spade in hand.  Then ♦A, ♦K and the ♠Q discarding a small club will put West on play, forced to lead a club or give you a ruff and discard.

If you cover the ♦10 with the ♦J, you might not be able to deny East a diamond entry to play a club through you.

On the actual layout of the cards, you can still succeed if you do play ♦J at trick 2.  You win with the Ace and later play the ♦6 from hand, ducking if West plays the 8 or 9 and rising with the ♦K if West plays low.  This line would fail however if the diamond suit was less favourable for declarer.

Even when your style is to signal to show length, there are times when you can make a nore meaningful signal.  With this diamond holding, why not play the Q♦ as East at trick one.  This card guarantees holding the knave.  Then at trick 2, West can lead a low diamond for East to win.  At this point, East knows there are no more diamond tricks to take so switches to the 8♥.  Now all West has to do is cover Souths card to ensure that he will eventually come to 2 tricks in the suit.

Win the A♥ and draw trumps (let's say West shows out on the first trump so 3 rounds are needed)

If you win the third trump in hand you can now make the key play of a low diamond towards dummy's 10.  If West rises with the Queen and switches to a club, you try the Queen and that loses to the King.  East exits with a heart which you ruff to play a second low diamond.  If West wins the Ace and plays a second club, you win and cross back to hand with a trump to cash 2 winning diamonds (discarding clubs) giving you 10 tricks. If East happens to hold the Queen or Ace of diamonds, then it is highly likely that West holds a club honour.  

Declarer ruffed the second heart and played the ♠K, which held the trick. West took the low trump continuation with the jack and forced declarer with a heart, reducing declarer to two trumps, the same number West had. Now, no matter how declarer played, West would make both his remaining trumps to defeat the contract.

As ever, dummy was critical of the line chosen. "If trumps had been 3-2, then almost any plan would have succeeded," he offered, "so you should have thought about overcoming a 4-1 break in trumps.

"You had to ruff the second round of hearts, but you should have continued with a low trump at trick three. Suppose West had played his jack - you would still have had a low trump in dummy to take care of a heart continuation. It would have been no better for West to have played low, for then dummy's 10 would have won the trick. The continuation of a trump to the king would have left West in a position where he could have done no better than to have won and forced you with a heart.

"After discarding a club from dummy, you would have ruffed in hand and played the queen of trumps. This would have left West with just the J, the master trump, which he could have taken whenever he pleased while you ran the diamonds and, if necessary, the top clubs. You would have made 10 tricks by way of four trumps and six tricks in the minors."

Partner most probably holds 5 hearts for his pre-emptive raise, so it looks like the setting trick will need to come from the minors.  On the bidding South may well hold 6 spades together with a singleton heart.  You know from partners ♣2 that declarer holds an even number of clubs and hence also an even number of diamonds.  If declarer has 4 clubs then partner has a club ruff for an easy one off.  Can you prevail when declarer has a doubleton club and 4 diamonds?  

Given time, declarer will set up 2 extra club tricks for diamond discards so how do you stop that happening?

At trick 2 you must continue with the other top club.  If partner shows out, give him a ruff.  If partner follows, then play a third club.  Declarer will discard a diamond on this trick, but when you win the first round of spades and play a fourth round of clubs, partner can ruff, preventing the crucial extra diamond discard.  In the fullness of time, East will take the setting trick in diamonds.

After getting the news about the unavoidable trump loser, declarer paused to consider what he needed to make the slam. Obviously, he needed to play four rounds of diamonds with East following suit so that he could discard two of his club losers. If this came to pass, the fifth diamond would provide a place for his last club, restricting the defenders to East's trump trick.

Declarer realized that if East started with four diamonds, he would be twice as likely as West to have the ♦J, so South finessed the ♦9 at trick four. After it held, declarer cashed ♦A, crossed to dummy with the ♥K and played the ♦K and ♦Q, discarding clubs from his hand as East helplessly followed suit. When East ruffed the next diamond, it was a trick too late as declarer discarded his last club. This was the only trick declarer lost.

Note that if it had been West rather than East who had the trump trick, declarer would have started diamonds by cashing the ace and then finessing dummy's 10 on the same logic that led him to the winning line on the actual layout: To make the slam, declarer needed for the opponent with the trump trick to follow to four rounds of diamonds.