Going into 2010 the top 20 players in the rankings look set for another dramatic shake-up.
It would be unwise to expect too much movement right at the top of the standings as the points difference between the 'big guns' makes their place almost guaranteed unless form (or more likely fitness) adversely effects their campaign. That said, Rafael Nadal is beginning to look a little uneasy as world No.2 unless his hard court form improves and his clay-court domination remains intact - and neither of those is a given. Novak Djokovic is hot on his heels.
Andy Murray, Juan Martin Del Potro and Nikolay Davydenko should all remain there or thereabouts during the new season.
Expect gains to be made by the likes of Jo-Wilfried Tsonga, Gael Monfils and Marin Cilic - this trio represent our 'three to watch' in 2010 - whilst it could prove to be a tougher campaign for the likes of Andy Roddick, Fernando Verdasco and Fernando Gonzalez.
| = | Roger Federer | Big enough lead to retain top spot for another year |
 | Rafael Nadal | Over-reliant on clay court form and fitness remains an issue |
 | Novak Djokovic | Late 2009 form can be used as basis for a rise in 2010 |
| = | Andy Murray | Unless he wins a Slam another year of being a 'nearly man' |
| = | Juan Martin Del Potro | A threat to Murray but still needs consistency in his game |
| = | Nikolay Davydenko | Expect another solid year for the ever-reliable Russian |
| Andy Roddick | No longer an improving talent, vulnerable to new generation |
| Robin Soderling | Big strides last year but will be hard to retain lofty ranking |
| Fernando Verdasco | Wins too rarely to deserve a top ten place, under big threat |
| Jo-Wilfried Tsonga | Looks set ot fulfil potential and climb higher in the standings |
| Fernando Gonzalez | Chilean has the ability but no longer youth on his side |
| Radek Stepanek | A battler but others no appeal more as tournament winners |
| Gael Monfils | Finally... finally starting to show how good a player he is |
| Marin Cilic | Destined for the top the Croat looks a cert to climb the charts |
| Gilles Simon | Not a great year in 2009 expect better from Simon this year |
| Tommy Robredo | Can still win but others now appear to be moving past him |
| David Ferrer | Winless in 2009 the Spaniard is taken to bounce back |
| Tommy Haas | Has the ability but not the legs to retain top 20 status |
| Mikhail Youzhny | Late flourish to last year masks career under-achievement |
| Tomas Berdych | Should be higher in the rankings, set to rise again in 2010 |
Further down the listings guys like Tommy Haas, Tommy Robredo and Mikhail Youzhny could well be vulnerable to improving talent.
Expect the No.25 ranked American, Sam Querrey, to continue his development in 2010, Richard Gasquet also has very few points to defend after his problems in 2009 and he should shoot up from a current placing of No.52 along with another Frenchman, Jeremy Chardy, who can significantly improve upon his standing of No.32 in the world.
All in all, it promises to be a great year on tour with several familiar players facing a real battle to survive and a few new kids on the block looking set to make their mark.
