This is aHand:

You play in 3NT after a straightforward bidding sequence and West makes a nuisance of himself by leading a Heart.

Although this guarantees two Heart tricks for your side (you play low from dummy at trick one, of course) it runs the risk of the ♥A being dislodged prematurely from the table. Sure enough, East wins the ♥K at once and promptly returns a Heart, taking away the entry to those lovely Clubs. Now what?

A count of tricks shows that you have two Hearts and five Diamonds. You can set up at least three Club winners but how can you reach them? It would be easy enough if the ♣A were to appear on the first round but these opponents didn't learn the game just yesterday.

Well, you just have to play on Clubs so you lead the ♣K, which holds (naturally – no rational defender is going to win the ♣A too early!) However, what Club did you play from hand? The ♣7, of course! You must conceal the ♣2 and hope this scrambles the opponents’ signals.

When you imperturbably lead the ♣Q at the next trick East has a real problem. Was his partner’s ♣3 the start of a high-low from ♣3 2 or was it the lowest card from three low Clubs? Unable to determine the true position, and unwilling to allow you access to all those Clubs, East plays low and you have stolen your ninth trick. Having pinched the second Club trick you can grab five Diamonds and the ♥Q before conceding the last three tricks.

Was East to blame for ducking the second Club? Not really. If your low Diamond had been a low Club and West really did have ♣3 2 doubleton his defense would have been right.