Origin of Deuce: Etymology
The origin of deuce can be traced back to the Latin word for two, duos, or perhaps more appropriately the French word for two, deux, as tennis has its roots in France.
Beyond that, it’s unclear how the number two relates to the game in the context of scoring. However, one prevailing theory suggests it stems from the following French phrase: à deux le jeu.
Of course, one can interpret the translation of this phrase as ‘to both the game,’ meaning two players with equal chances of winning the game or ‘to two the game,’ referring to either player needing two points to win the game.
It’s unlikely we’ll ever know the true origin, but I’ll leave the official debate up to the tennis historians.
Despite historians pinpointing the origin of tennis in France, they don’t use the word deuce at the French Open. Instead, you’ll hear the chair umpire state “égalité,” which translates to “equality.”