So you’ve played tennis, or at least watched it on the TV, and you have realized that the scores don’t go up by one point each time. If you’re not familiar with the tennis scoring system then here’s a brief explanation: The first player to win four points wins a game, if a player wins four points straight their scoring will go 15, 30, 40 then game.
Well there’s no solid reason why the scores go up like they do but tennis does have medieval and French roots. The only believable explanation is that the scoring system is based on the number of minutes in an hour. Back in the fifteenth century, each turn had four winning rallies worth 15 points each.
It was realized that when both sides were at 45 points each, it would be necessary to win two rallies otherwise the game could be decided by luck. Doing this would mean that the total would be more than 60 points, which would mess up the minutes in an hour idea. So the score was then altered to 40-all and 10 points were given for each rally won. If there was a tie at 50 points, the score would go back to 40-all. Therefore you could only beat the opponent by winning two rallies in a row. Makes sense really.
The term ‘deuce’ came from the French ‘deux’, which means two consecutive points are needed to win.