One-all

One-all was a state where two players had each won one game between then beforehand, meaning they were tied in a deadlock. To break the deadlock, and subsequently find the true victor between them, they had to play a third game to make it a best of three contest. 
The Fourteenth Doctor noted this was the situation he and the Toymaker were in shortly after he lost their game of Cut in 1925 Soho, with him having previously bested the Toymaker in their first game "many years ago". (TV: 
Category:Games