Dead rubber is a term used in sporting parlance to describe a match in a series where the series result has already been decided by earlier matches. The dead rubber match therefore has no effect on the winner and loser of the series, other than the number of matches won and lost.
The term is widely used in Davis Cup and Fed Cup tennis, as well as in international cricket, field hockey, the FIFA World Cup, UEFA Champions League and Rugby World Cup.
For example, in a Davis Cup series, each pair of competing countries play five matches (rubbers) where the winner is decided on a best-of-five basis. Once one team has reached three victories, the remaining match or matches are said to be dead-rubbers. International Tennis Federation's last revision of the competition policies on dead rubbers is from 2011.
Because the result of a dead rubber has no impact in determining the winner of a series, dead rubbers are played in a less intense atmosphere, often allowing the lesser team to sneak a win. Sometimes, a second-string player who has not played much in top-level competition is used to play a dead rubber in order to gain experience. This makes completing a clean sweep of the series less likely.