rule of eleven
This is a valuable rule that is most commonly used by the partner of the opening lead but can also be used by declarer.
Subtract the value of the card led from number 11.The resulting number is the number of cards outstanding which have a value higher than the one led.
For example if a 4 is led. Subtract 4 from 11 = 7. This means that there are seven cards higher than the 4 in both dummy, partners and declarers hand