Tennis System

Please explain the ranking system used in professional tennis. How are points accumulated?
If you’re familiar with golf, it’s quite comparable. Points, and consequent rankings, are earned based on performance in tournaments. Players can only count the results of their best 18 tournaments (so there’s no extra advantage in playing tons of events). There are 13 mandatory events: Grand Slams and Masters Series tournaments. If a player isn’t ranked high enough to qualify for one of the mandatory events, they may substitute another tournament in its place. If a player who qualifies for a mandatory event skips it (injury, laziness, etc.) it still counts as one of their 18 events and they earn 0 points. The year end top 8 get to include their results from the year end championships too, as a 19th tournament.
