- Players win points for participating in ATP-sanctioned tournaments

- The number of points won depends on how far the player progresses in the tournament. Details of the points awarded are in the table below.

- The maximum number of points a player can win depends on the nature of the tournament as defined by the ATP. For example, a 500 series tournament has a maximum of 500 points on offer, while an ATP 1000 Master tournament has a maximum of 1000 points on offer.

- Players accrue points with every tournament they participate in, and the cumulative points at the end of the season determine the year-end ranking.

- Now it gets slightly complicated, so pay attention

- Points won by a player in one year in any given tournament are "dropped" the next year from his total points when the same tournament is held again and points gained from his performance in this, the latest edition of the same tournament, are added. Here are two examples to illustrate this.

Example 1: How a player can lose points

Suppose Rafael Nadal wins the US Open in 2012, which means he will get a total of 2000 ranking points from this tournament. Consequently, he will have to defend those 2000 points in 2013.

Assuming he loses in the US Open semi-final in 2013, based on the table below he will lose a total of 2000-720 i.e. 1280 points when the rankings are updated. So if his ranking points total going into the 2013 US Open was 12,000, they will drop down to 12,000-1280 i.e. 10,720 points immediately after a tournament.

Example 2: How a player can gain points

Now suppose Roger Federer loses in the final of the 2012 US Open, which means he'll get a total of 1200 points.

If he wins the 2013 US Open - he will win a gain a total of 2000-1200 i.e. 800 points. So if his ranking points total going into the 2013 US Open was 11,2000 ,it will rise up to 11,200+ 800 i.e. 12,000 points immediately after the tournament.