Does anyone know where the scoring system originated from? I've tried to research it but not come up with anything that seems remotely plausible.
The origins of the 15, 30, 40 and so on are not known, but have medieval and French roots. One possible explanation is that the scoring system is based on the presence of a clock face at the end of the tennis court. A quarter move of the appropriate hand was made after each rest, with the score being called as 15, 30, or 45 as the case might be. As the hand was moved to 60, making the complete circuit, this was the game.
The term "deuce" is derived from the French "deux", an advantage of two points having to be gained.
"Love" is generally taken as being derived from the French "l"oeuf", the egg, symbolising nothing. The term "love" can also be said to come from the English phrase "neither for love nor for money", indicating nothing.