We think this system is complicated - look at what used to happen!
"Yet without the foresight of ATP founding fathers, the rankings landscape may look entirely different. From the dawn of Open Era tennis in 1968, rankings were largely a subjective calculation, generated by national tennis associations, circuits and a number of eminent tennis journalists who compiled their own lists".http://www.atpworldtour.com/News/Tennis/2013/08/34/Heritage-1973-ATP-Rankings-Celebration-Part-I.aspx
Laundry - I think we're getting closer to agreement! As I understand it...
For players starting the year in the top 30 (commitment players), count
WTF (if played)
+ 4 Slams
+ 8 x Masters 1,000s
+ 6 others (500s, 250s, Davis Cup World Group, Olympics, Challengers, and Monte Carlo can be counted here). To count their best six, players must have fulfilled their commitment to 500 events - 4 total per year (at least 1 after the US Open). There's a 0 point penalty lasting 12 months for any less than 4. Points from extra tournaments go in to non-countables but can be used later if other points are not defended successfully.
For players outside top 30 at start of year it seems to be
Any Slams entered
+any Masters 1000s entered
+best of rest up to a total of 18 tournaments. No minimum requirement for 500s.
Going back to Andy - let's hope he does well in Tokyo - he can gain some points on last year. He'll get another 0 point penalty if he doesn't play Valencia/Basel - but he may prefer to save his energy for Paris and WTF.