The rules of tennis are that: The first point of a game is served from the right-hand side of the court. After that, sides alternate. Therefore: Anything with an even number of points played (0-0, 15 all, 30 all, deuce, 30-0, 0-30, 40-15 and 15-40) is served from the right-hand side of the court - this is why it is sometimes known as the "deuce court".
https://sports.stackexchange.com/questions/25861/in-tennis-how-to-find-out-the-service...