Rankings on both the ATP World Tour and the WTA Tour are determined by calculating a player's total points over the preceding 52 weeks. Tournaments award greater or fewer points depending on the tournament's level, and players are awarded points based on how far they make it in a tournament.
The amount of points a player is awarded varies greatly depending on the tournament, with Grand Slams awarding the most points per round. On the WTA Tour, Grand Slams award champions 2,000 points, while a mid-level event such as a Premier 5 tournament awards champions 900 points. At the bottom, an ITF Circuit event awards its champion as few as 12 points.
World rankings on both tours are based on the player's performance over the preceding 52 weeks. The ATP World Tour rankings are based on the player's total points over his previous four Grand Slams, his previous eight ATP World Tour Masters 1000 events, the last Barclays ATP World Tour Finals of the ranking period, and his six best results from his last ATP World Tour 500, ATP World Tour 250, ATP Challenge Tour and ATP Futures tournaments. Players are permitted to petition for a protected ranking due to injury if they are unable to play, allowing their rankings to stay stable as they recover.