The scoring system of tennis is somewhat arcane and the origins are not well understood. It is likely tennis derives from game played in medieval France in which a clock face was used to keep score. Points in the games were incremented in multiples of fifteen (the 'forty' call is thought simply to be short for 'forty-five', and sixty, the top score, was never called as the game ended when this score was reached). Other peculiarities of tennis scoring include the term 'deuce' and 'love'.
Is 'deuce' a corruption of the French phrase 'à deux de jeu' meaning 'two points away from the (end of the) game'?