In Bridge, the Law of Restricted Choice allows declarer to adjust his estimate of the probablility of a particular opponent holding a particular (high) card.  Let's say declarer's side has 10 cards of a suit to the AQ10.  The KJx are held by the opponents. Those 3 cards could be split in a number of ways.  With no information, the K could be behind the AQ10, it could be singleton, it could be KJ doubleton, and so forth.

So declarer lead low towards the AQ10. The first opponent plays the J. What should declarer do?

Take another case -- declarer holds the AQ9 missing the KJ10 in the same situation and the first opponent plays the J. What should declarer do?

I found an interesting article on WikiPedia that relates to the Law of Restricted Choice: click to view. The article is very long, but you will like the front part of it, I guarantee!

An actual article on Bridge's Law of Restricted Choice is here. There are several others on the Internet as well.  If you have any interest, just Google it.