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

West leads the ♥A (ace from ace-king) against your 4♠ contract, East discourages with the four. West switches to the ♦3 at trick two. What are your thoughts?

Solution:
The ♦3 has the ominous look of a singleton, and the defense threatens to engineer a diamond ruff. If East has the ♠K, then the contract is safe. In the more likely case that West has three spades to the king, as he has made a takeout double, you need to be careful. With your current trump holding, the usual precaution against a ruff is to spurn the finesse and play the ace and queen of spade. However, that is not the right precaution on this deal. If you win the diamond return at trick two and play a spade to the ace followed by the ♠Q, West will win the ♠K, play a club to East's ace and receive a diamond ruff.

Forewarned is forearmed. The bidding has given you enough clues about the East and West hands - West is likely to have three spades to the king and the ace and king of hearts, and East should have the ♣A for his free bid of 2♣. You should stymie the threat of a diamond ruff by leading the ♥Q at trick two and discarding the ♣9. This loser-on-loser play has the effect of disrupting communication between the defenders, and as a result East cannot gain the lead any longer to give West his diamond ruff. This maneuver has been aptly named the Scissors Coup, as it takes on the role of a pair of scissors to cut defensive communication.

Analysis:
Bridge Baron's double dummy solver asserts that the Scissors Coup maneuver of playing the ♥Q and discarding the ♣9 at trick two is required to make the contract. The double dummy analysis also revealed that an opening diamond lead would set the contract, because the ♥A has not been dislodged, and the loser-on-loser play is no longer possible.
Par Contract Analysis:
The par contract on this deal is 5♣X by East-West (who are not vulnerable), interetingly enough as a sacrifice over 4♦ by North-South.

Bridge Baron deal No : N3151-78802-02207-56302-79040-92921