West   North   East   South
                                 1♠
2♥        2♠       pass   3♦¹
pass      4♠      all pass

1 - help suit game try

5♦ is the contract to be in, but the auction shown here is the one that occurred at the table. West leads the ♥A and continues with the ♥K, East plays high-low, you ruff in hand. Plan the play (when you tackle diamonds, West kindly produces the ♦Q on the first round, solving your guess in the suit).

Solution:
After ruffing the heart continuation at trick two, you should cash the ace and king of spades, West playing the ♠10 on the second round. You should now turn your attention to the diamond suit (the singleton ♦Q with West solves your guess in the suit), and keep playing diamonds. If East ruffs in at any stage, he will be forced to play a club into dummy's tenace. If East refuses to ruff, you will exit with a spade to inflict the same throw-in.

If West happens to have three spades and ruffs one of your diamond winners, you will be forced to rely on the club finesse. The recommended line is more likely to succeed, though.

Analysis:
Bridge Baron's double dummy solver confirms that the suggested line of play is required for success. The double dummy analysis also points out that a club switch at trick two (or an unlikely opening club lead) breaks the endplay.
Par Contract Analysis:
The par contract on this deal is 5♦ by North-South.

Bridge Baron deal No : N0725-23883-50126-77609-48709-52273