How To Score Ping Pong

It's a bit tricky to learn how to score ping pong; not everyone follows the same rules, for instance.  Since the 2000's, people have used the new scoring system to rack up ping pong points, but the old system is still used in some areas of the United States and Japan.  So how do you score these points?

1. You earn one point for each ball your opponent cannot hit back.  This is true for any ping pong scoring system you use.  You cannot earn a point if the ball isn't returned because it touches the net. This is called a let serve, and must be replayed again.
2. If you use the new system, you can only win if you reach 11 points.  Again, all serves must be legal in order for you to win.  You also must be at least two points ahead of your opponent; if you're not, you must play until either side is two points ahead to declare the winner of the game.
3. If you use the old system, you can only win if you reach 21 points.  Again, you must be at least two points ahead to win.  If you not ahead by at least two points, you must play until either team is two points ahead.  There is no limit to how many serves you can do.
4. Games are also scored; the winning player depends on who wins a certain amount of matches.  If you use the old system, you will have to win two out of three games to win. Alternatively, if you are playing a best of five match, you must win at least three game to win.  People who use the new system will need to win three out of five games or four out of seven games to win.