Love-15-30-40. If you’ve ever played tennis, or just enjoy watching it, you know that this is the game’s basic scoring system. And you probably think it makes no sense whatsoever. If you’re counting by 15, you hit 45, not 40. And “love” isn’t a number at all!
It’s a weird system. And there’s a good amount of debate as to why this is the scoring, with the most likely explanation involving a weird confluence of eggs, the English, clocks, and the inability to divide an odd number by two without a resulting remainder.
Let’s start with the eggs. Eggs are, of course, oval-shaped, much like the number zero. And in a few sports, they’re used as such: “Goose egg” is a common phrase in American sports, and “duck,” short for “duck’s egg,” is common in cricket. It is believed that tennis is also included in this list. Why? Tennis originated in France in the twelfth century, and many of the rules and terminology created at this time for the sport have been carried through history and across countries. One of these terms is the French word for “the egg”: “l’oeuf.” If you’re not a French speaker, this term sounds a lot like the English word “love.” It is likely that a series of English speakers simply replaced the French word with its English homophone.
As for the numbers 15, 30, and eventually 40? The most likely explanation involves a pretty simple way to keep score: clock faces. The first point in a game would earn you one quarter of a revolution around your clock, or 15 (minutes or seconds). The second point moved you to 30, and the third to 45. When the game ended, both opponents’ clocks would be reset. Easy—except that tennis games have to be won by two or more points. If both players were on a 45, then what? Moving the hand halfway to 60 wouldn’t work: There’s no 52.5 on a clock.
A little creativity was in order. The solution: Move the hand to 40 for the third point, instead of 45. When players tied at 40-40 (“deuce”), the next point would be worth 10, moving the clock to 50. If the same player earned the subsequent point, he or she would get another ten points and win the game. If not, his or her clock would be reset to 40, and the players would be tied at deuce again until one player scored two consecutive points.
There are alternative theories given for both oddities as well. Given how far back the origins of the sport date, the full story behind the scoring lies only with those who are since long gone. However, given what is known, the previously detailed theories are most likely.