Contract bridge: Assume everything is wrong and seek a method still to prevail

If you pay this deal little attention, you will still make your contract over half the time. However, a good bridge player makes it all of the time. Can you find that line?

Bidding
Dealer: South
Game All

If the spade finesse works — or it fails but the suit divides 3-3 — you are home. Should the spade position prove unfavourable, you have the diamond finesse on which to fall back. But what if the diamond finesse is wrong too? Can you still prevail?

The key is calculating in which order to tackle these suits. Assume that West holds five hearts (if hearts are 4-4, things are easy), placing three hearts with East. You want to risk the spade finesse and East winning only once East does not hold any hearts. 

Duck trick 1 and win the continuation with K♥. Cross to dummy’s A♣ and lead 2♦, taking the finesse when East plays low. West wins K♦ and leads a third heart, clearing the suit. Now, return to hand with K♣ and lead a low spade, again finessing when the first opponent plays low. If East ducks, come back to hand with A♦ and try again. When East wins K♠, he has no hearts to return.

Played in any other order, you will lose both finesses and three hearts whereas, this way, despite both finesses being wrong and neither suit splitting evenly, you still emerge with at least nine tricks.