1
general::
1. See under PLAY BOTH ENDS AGAINST THE MIDDLE. 2. Break a tie by playing an additional game or period, as in Each team had won three games so they had to play off the tie to decide the championship.
American Heritage Idioms
2
general::
Phrase(s): play something off
to play a game to break a tied score. • They decided not to play the tie off because it had grown so late. • They went ahead and played off the tie after all.
McGrawhill's American Idioms And Phrasal Verbs