Whats the Rule?

Unfair Rule?

Player A mistakenly serves the first three points of a game and is up 40-love. The players then realize that Player B should have been serving. According to the rules, Player B serves the next point down love-40. In this situation, Player A will serve for the set if he goes on to break Player B. Since Player B has not come close to breaking serve, Player A will most probably win the set, benefiting greatly from serving out of turn. Wouldn't it be more fair to have Player A finish serving the out-of-turn game, and for Player B to serve the next two games, restoring the original order of service?

The Rules of Tennis, in this case Rule 27, do not presume that one player or another is either advantaged or disadvantaged by serving or receiving. When a player serves out of turn, any points played stand and the serve reverts to the correct server, unless the game has been completed, in which case order continues as altered (Rule 27.c.). While it's common to view service-order errors as the fault of the server, both players are equally responsible. If you and your opponent can agree on a fairer resolution, you may, but in the absence of an agreement you'll need to follow the rules!