The Crossruff. Where there is no attempt to draw trumps, but the declarer and dummy make their trumps separately
For example:
 7 K J 9 8 K 9 4 10 9 7 5 4 |
||
| K 8 5 5 2 Q 10 3 A K Q J 3 |
Q 10 9 4 3 6 4 3 J 7 6 8 6 |
|
| A J 6 2 A Q 10 7 A 8 5 2 2 |
Contract: 4 by South
Lead: K
The A follows, and South ruffs. His only hope is a crossruff. He counts one spade and two diamonds winners, three spades ruffs in dummy, four club ruffs in hand, and the King of trumps.
This gives a total of eleven tricks. As he has the high trumps in bouth hands he is in no danger of an overurff.
But before embarking on the crossruff the declarer must comply with the following rule: “Cash winners in the side suits before starting the crossruff”.
Unless this is done, East will be able to get rid of diamonds an the clubs, and the diamond winners will be endangered.