The running score in each game is described in a manner unique to tennis. Scores of zero to three points are described as "love" (or "zero"), "15", "30", and "40", respectively. The origins of the 15, 30, and 40 scores are believed to be medieval French. It is possible that a clock face was used on court, with a quarter move of the hand to indicate a score of 15, 30, and 45. When the hand moved to 60, the game was over. However, it was realized that the game could then be won by luck, and so the idea of "deuce" was introduced. In order to make the score still within the ""60"" ticks on the clock face, the 45 was changed to 40. Therefore, if both players have 40, the first player to score receives ten and that moves the clock to 50. If the player scores a second time before the opponent is able to score, they are awarded another ten and the clock moves to 60. The 60 signifies the end of the game. However, if a player fails to score twice in a row, then the clock would move back to 40 to establish another “deuce”Another theory is that the scoring nomenclature came from the French game jeu de paume (a precursor to tennis that substituted the racquet for a hand). Jeu de paume was very popular before the French revolution, with more than 1,000 courts in Paris alone. The traditional court was 90 ft in total with 45 ft on each side. When the server scored, he/she moved forward 15 ft. If he/she scored again, he/she would move another 15 ft. If he/she scored a third time, he/she could only move 10 ft closer
