Rankings
These are the ATP Rankings of the top twenty singles players, doubles players, and the top ten doubles teams on the ATP Tour, at the end of the 2008 ATP Tour, and of the 2009 season, with number of rankings points, number of tournaments played, year-end ranking in 2008, highest and lowest position during the season (for singles and doubles individual only, as doubles team rankings are not calculated over a rolling year-to-date system), and number of spots gained or lost from the 2008 to the 2009 year-end rankings. The 2008 year-end rankings include the number of points under the 2008 points system, and doubled, as they were at the end of the year by the ATP, to fit the 2009 points system (the doubles (team) rankings points were not doubled, as they were calculated under the ATP Race points system in 2008). The doubled year-end rankings were never officially published though, as the first rankings of 2009 already counted the drop of the 2008 season openers' points due to a calendar change.
Read more about this topic: 2009 ATP World Tour