Crossruff

In bridge, a crossruff is a method of scoring tricks by ruffing losers in both declarer's hand and dummy. The following 8-card ending illustrates this concept. South is on lead and spades are trump.

		Dummy
		T987
		5432
		—
		—
West				East
6542				3
AKQT				J8
—				AKQJT
—				—
		Declarer
		AKQJ
		—
		8652
		—

If South draws the opponents' trumps by playing his top spades, he will be left with four diamond losers. The better strategy is to "crossruff" the red suit losers. South should ruff a diamond in dummy, then ruff a heart in hand, and repeat the process to collect all 8 tricks.

		Dummy
		T842
		4
West		AKQ4		East
Q65		7432		KJ973
QT52				K96
32		Declarer		876
QJ98		A		T6
		AJ873
		JT95
		AK5

In this deal, South's contract is 6. West's opening lead is the Q.

South has a sure club loser and must do something with all his heart losers. Having avoided a trump opening lead, South can aim to crossruff the major suits. Before starting, however, he cashes the K. This is important in case the opponents discard clubs during the crossruff, and can threaten to ruff the K later.

At trick 3, South plunks down the A, the A and ruffs a heart in dummy. Next comes a spade ruff in hand, followed by another heart ruff. Another spade is ruffed by declarer. The layout is now:

		Dummy
		T
		—
West		AK		East
—		74		KJ
Q				—
32		Declarer		876
J9		—		—
		J8
		JT
		5

Now South can ruff two hearts in dummy and and score two trump tricks in hand. He loses just one club trick in the end.

If South hadn't cashed the K early on, however, the situation would be:

		Dummy
		T
		—
West		AK		East
—		743		KJ
Q				—
32		Declarer		876
J98		—		T
		J8
		JT
		A5

When South ruffs a heart in dummy, East discards a club. Now South must lose two club tricks - East will ruff the A, and West will still get a club winner for down one.