Suppose you return the ♠K at trick 2.  It is not difficult to see that you be subjected to a squeeze in the black suits as South is marked with long diamonds and all the outstanding values.  Declarer will win the spade, cash all his trumps, and cross to dummy with the ♣A.  the ♥K will then squeeze you as you have to make a discard from ♠Q, ♣ QJ.  There is a defence to this squeeze and that is to make an early attack on the squeeze card.  If you reyrn a heart at trick 2, South must make a premature discard.  He probably throws a club, but then East retains the top spades in his hand in the endgame and trusts partner to look after the club suit.  On this hand, the saving card is West's ♣8

You have 4 trumps, 2 clubs and a club ruff and 2 diamonds to take.  The tenth trick could come from a diamond finesse (unlikely on the bidding), a 3-3 spade break, or perhaps an endplay on West. The latter option is also not very likely as they defence will have time to unscramble the spade suit unless West has a very specific holding e.g. AK doubleton.  Hence your best play is to try and establish the long spade.  You don't want East coming in twice to play diamonds through your holding and hence you should make the first spade play from dummy.  This play makes it much harder for East to win the tricks the first 2 times spades are played (indeed impossible on the layout shown).  If you make the first spade lead from hand, the defence is very much easier to find as East win win cheaply with the ♠T.  Best play is therefore to win the trump in dummy and lead a spade immediately, just covering East's card.

Presumably partner would play the 7 from a heart holding of A976, so it looks as if you will be able to take another heart trick.  The ♠A is a third trick and if partner leads a diamond when in with the ♥A, the ruff will beat the contract.  How do you go about getting your ruff?

The problem with playing another high heart is that partner will not overtake, losing his entry.  One way to avoid this would be to lead a low heart at trick 2.  This would force partner to win the Ace. However, there is no guarantee that East will return a diamond as a club switch may look very attractive from his point of view.  You might try cashing the ♠A before exiting with a low heart.  This should pinpoint the ♣A with South (if East is awake).  There is a better play than this - at trick 2 switch to a high club.  Then win the ♠A at the earliest opportunity and return a low heart.  East will be forced to win and the diamond switch should now be completely obvious as the only possible setting trick.

The 4-0 trump break is awkward.  You have 3 certain trump losers but it looks as if you can use the spades to take care of any losing clubs. If you play another trump towards dummy you will be alright if West takes the Ace and say exits with a another diamond.  You can ruff and then play spades.  Although West will ruff in, the Queen of hearts will serve to draw West's last trump whilst at the same time being an entry for the spades.  However, this line is not foolproof.  If West has the foresight to duck the second round of trumps, dummy's late entry to the spade suit has disappeared and you will eventually lose 3 trumps and a club.  The winning play is to play on spades as soon as the 4-0 trump break comes to light.  West will have to ruff at some point and will probably exit with a diamond.  You ruff and now play a trump to the Queen.  Since West has been reduced to 3 trumps, he can no longer prevent you accessing dummy and will be held to just his 3 trump tricks.

Despite having a certain trump loser, there are various chances to avoid a diamond loser - the suit might break or you might be able to engineer an end-play.  Given that East probably holds seven hearts, a 3-3 diamond break must be against the odds.  The best line is to take a third top club, 2 top diamonds and then your major suit winners before exiting with a trump.  By this time West will only have spades and diamonds left.  A spade to dummy's Ace gives you a diamond discard whilst a diamond will be fatal if East started with honour doubleton in the suit.

You almost certainly have 2 club losers so you must avoid losing 2 trump tricks.  The bidding almost certainly places the ♠K with East and you must not take a first round spade finesse.  Laying down the  ♠A will save you when the layout is as shown.

Did you think that declarer had ♥Kx and continue at trick 2 with a safe spade? 

Consider East's card - the 2 would show an odd number in standard methods and on the bidding this is probably 5.  Secondly, if South did have a doubleton spade and a diamond loser, then leading the ♥A will be sufficient to beat the contract.  Declarer has made a standard deceptive play at trick 1.  He plans to throw a diamond on the ♠A and then set the diamond suit up with a ruff.  Don't be fooled - You should lead the ♥A at trick 2 and continue the suit when partner encourages. 

It looks like you have a diamond trick.  Partner played the 9 at trick 1 so declarer must have the ♦8.  Your 2 Aces mean that another trick must be found and that can only come from a club ruff.  You need to hope that partner has a doubleton club and play this suit after winning the ♥A  Dummy will win and declarer will hopefully have no quick way off the table to draw the trumps.  If he plays a diamond, you will win and play Ace and another club, giving partner a ruff.  By the way, you did remember to lead the ♣Q on the first round didn't you?  If not, declarer can run the club to the nine in his hand, and draw the remaining trumps.   

Presumably south has a doubleton club and partners 9 is a suit preference signal for spades.  Did you switch to a spade at trick 3?

If you return a spade, declarer wins the Ace, plays the ♦A and ruffs a diamond, returning to dummy 3 times in trumps to set up and cash the long diamond for a spade discard.  Although partner has shown values in spades, your strong diamond holding prevents declarer from using dummy's diamond suit provided you attack the entries to the table.  A trump return at trick 3 takes away a dummy entry before the diamonds are brought into play and declarer will eventually have to lose his spade tricks.  Partner was right to show his spade valus with the ♣9 but signals from partner should be viewed as information, not commands.  On this hand, your diamond holding is good enough to prevent discards; with a diamond suit of say 3 small, a spade switch would be essential to cash any tricks that might be going.

You look to have a club loser in addition to the Ace of trumps.  However, if you could force a club lead from the player that wins the ♠A, your chances would greatly improve.  What is the best way to do this?  Try the effect of crossing to dummy to lead the ♠J.  If East has ♠Ax he may well duck, perhaps playing his partner for a singleton King or Queen of spades.  If he ducks, you can cash the other diamond before exiting with a trump.  This will force the defence to give you a ruff and discard or open up the clubs.  On the actual layout, East has a singleton spade so has to take the Ace on the first round.  Does this spell certain defeat?  At the table, the contract still made.  East was beset with the notion from declarers play that partner held a key holding in spades - Qx say.  When in with the ♠A, East played a fourth round of hearts to promote partners presumed ♠Q and the ensuing ruff and discard handed the contract to declarer.  South did well to play as he did; the defence could hardly go wrong if he had started the spades from hand.  A mark of a good player is that he constantly sows seeds of doubt in defenders minds.

Sound technique is to ruff the second spade high, cross to hand with a trump and ruff the remaining spade high - on this trick East plays the ♠Q.  Now draw the remaining trumps (they break 2-2). Then cash ♥AK and ruff a heart - both follow but the Queen does not drop.  By this time you can place West with ♠AKJxxx and probably only 3 hearts as else he would have a 64 shape in the majors and 10 points and would most likely have opened 1 spade rather than 2.  So now you can cash the remaining trumps, discarding the ♣J from dummy. At this point, West will have a spade and 2 clubs, whilst East will have a heart and 2 clubs.  All you have to do is play off the 2 top clubs and claim.

You have 7 top tricks and various chances to develop 2 more.  It's not much use playing for hearts to break 3-3 as that will only generate one extra trick  and will probably generate 4 losers in hearts and clubs putting you under pressure.  A simple line is to win the club and take an immediate spade finesse.  If it loses, you will need to play the diamonds for 4 tricks by finessing the Jack and hoping for the suit to break.  However, if the spade finesse wins, you only need 3 tricks from diamonds so you should play this suit in the optimal way by cashing the King first, then the Ace and then back towards the Jack.  You are well rewarded on this hand as a look at all four hands will show.

You need an entry to dummy to make the ♦K.  You could try leading a heart to the Jack which gives you a 50% chance. However, it is better to play the hearts no worse than 4-3. Lead the ♥Q at trick 2. If the opponents take this, the heart Jack is an entry for the King of diamonds. If the ♥Q is ducked, play the Ace and ruff a heart. You can now discard a heart on the ♦K and try the club finesse for an overtrick.

Declarer is surely at leat 5-5 in his suits.  You  look to have 2 hearts and a diamond trick.  You wont be beating this contract if declarer is 6-5 or has a void club, so assume he has a 5251 shape.  Now if partner holds the ♣A and ♠9 you can prevail.  Switch to a club at trick 2.  Partner will win the Ace and return a heart.  Now a third heart allows partner to promote you a trump winner to go with your eventual diamond trick.  Everyone has met this kind of situation many times, yet somehow the right defence is seldom found.

There are no ruffs to be had in dummy so it looks like you will need the club finesse.  However, you can improve on this.  If trumps break then a dummy reversal sees you home.  Take the ♥A and ruff aheart at trick 2.  Now ♠T and a spade to the Jack reveals the trump break.  If they are 4-1 then you will be back on the club finesse but if they are 3-2, then ruff a heart with ♠Q and play a diamond to the Queen to ruff another heart with the Ace of spades.  Now cross to the ♣A and draw the last trump, discarding a club.  Your remaining diamond winners bring your total to 12.

You have been unlucky so far and you need some favourable lies from now on.  You hope to make 6 trumps, 2 clubs and the 2 Aces.  The normal method of tackling the heart suit would be to run the Jack and then take another finesse if the Jack has not been covered.  However, you won't make the contract if you play like that as you will then lack the entries to lead clubs twice towards dummy. Best play is a heart to your Ten, followed by a club.  West will duck and you win the Queen.  Now you can play the ♥J from the table, overtaking with the Queen.  Now the Ace of trumps draws the King and another club to dummy establishes your tenth trick with the ♠A as an entry to dummy.

The best chance on this hand is to assume that trumps are breaking 3-2 (or perhaps that someone has a singleton King). Ruff the opening lead and lay down the ♠A. Then just play on clubs. You hope to restrict the defense to just 3 trump tricks. The hands as shown are one of very many combinations that allow the contract to make.

The problem with playing a second top club is that you may be establishing the ten in dummy as the ninth trick.  If you play a low club at trick 2, declarer may score a trick with the ♣Q.  Since partner must be credited with the ♥K, it cannot cost to play a heart at trick 2.  In case declare holds the ♥9, you must switch to the ♥T.  Full marks if you got this one right, as this is not easy.