Tennis pointing system

The origin of this scoring comes from the (quarterly) stations of the clock, where "forty" was, presumably, easier to say than "forty-five." 

The definitive origin of the use of "love" for zero is not known but probably is derived from a popular saying about amateur sports. It is possible that the use of "love" for zero is from the French word for an egg (l‘oeuf because an egg looks like the number zero. "Love" as "zero" is also said to possibly derive from "l'heure" or "the hour" in French. When stating the score, the server's score is stated first. If the server announces the score as "thirty-love," for example, it means that the server has won two points and the receiver none.

http://en.wikipedia.org/wiki/Tennis_score

The idea was to have a 'day' comprised of 24 hours (4 times 6). Each set is 6 hours 'long', each hour is comprised of 60 minutes - the count progresses at 15 minute intervals: 15, 30, 45 and "60" = game. When the "deuce" was introduced, the clock was 'move back' 5 minutes to indicate you will not win with just one point (15 minutes will not get you to a full hour). BTW - "deuce" comes from the French word "deux" - "two", indicating you need TWO points to win.