You are South playing in a knockout team match. You open 1♦, LHO overcalls 1♥, partner raises you to 2♦, East comes in with 2♠. You have a tough call, and eventually choose 5♦ which ends the auction.

The contract has no legitimate play, as you have to lose at least one club, one diamond and one heart. This is your lucky day, as West gives the contract a reprieve by leading the ♠K. How do you plan to take full advantage of this friendly lead?

Solution:
West's lead of the ♠K suggests that he has led from a doubleton. You can get rid of two of your hearts on the queen and jack of spades. You need some luck in the trump suit - you need West to have the KQ doubleton or a singleton honor; otherwise, if you lead a diamond to the ace and try to discard your heart losers on the spades, West will ruff with a small trump. Therefore, you have to plan your line of play based on the assumption that West has a singleton honor or the KQ doubleton in diamonds.

While you have to hope for a fortunate trump layout, you need not rely on a 3-2 club break; you can cater to West having four clubs. To do so, you have to cash a top club before leading a diamond to the ace. When you lead a diamond to dummy's Ace, West follows with the ♦K, which is promising. You discard your hearts on the two good spades, West discarding a heart on the third round.

You now make another key play and lead a club from dummy, leaving East with no good solution. If East ruffs this, he will be ruffing your loser, and your task of establishing clubs will be made simpler. If East discards, you will win the King and concede a club to West (knocking out the ♦Q is okay too), and will eventually establish clubs by ruffing the fourth round of clubs in dummy. The reason behind cashing a top club at trick 2 was to play a club through East, catching him in the above-mentioned dilemma.

It might appear as declarer can succeed even if a top club is not cashed at trick 2. For example, declarer can play a diamond to the ace at trick 2, take two heart pitches on the queen and jack of spades, and concede a trick to the ♦Q. The problem with this reasoning is that when East is on lead after winning the ♦Q, he can force you by playing a heart, thereby preventing you from establishing clubs. A detailed analysis is available in the March 2nd 2007 Deal of the Week, when we presented this deal as a defensive problem.

Analysis:
The double dummy analysis confirms that even after receiving the friendly ♠K lead, the precise sequence of plays listed in the solution section are required to make the contract. It is worth mentioning the mandatory plays again:

Trick 2: Cash a club honor.
Trick 3: Play a diamond to the ace.
Tricks 4-5: cash queen and jack of spades, discarding two hearts from hand.
Trick 6: Lead a club from dummy.

Bridge Baron's Line of Play
Bridge Baron found the winning line on this deal, and cashed the ♣K before leading a diamond to the ace and taking two heart discards on the queen and jack of spades and leading a club towards hand. When East discarded to this trick, Baron won the ♣K and digressed from the recommended line by playing a diamond to the 10 and Queen. East returned a heart to force declarer, but Baron was in full control and conceded a club to West after ruffing the heart return. West played yet another heart, but Baron ruffed the heart, ruffed a club with dummy's ♦7, played a trump to hand drawing the last trump in the process, and claimed the last trick with the established club.

This deal is an illustration of the differences in the "thought process" of computers and humans. While the play of cashing a club honor is counterintuitive to most humans, Baron found the play pretty quickly.
Par Contract Analysis:
The par contract on this deal is 4♦ by North-South.

Bridge Baron deal No : N3088-70567-84208-30466-12722-42379