Could you show the math? When I was looking at the numbers, I could have sworn Federer didn't need to get that many points from Rome even if Rafa wins.
The points the players gained in Rome 2011 will be dropped in 2 days, at the next ranking (right when Rome starts). At this point they will also of course add the points from Madrid this week:
Federer : 8520(current) - 90(Rome 2011) + 1000(Madrid 2012, if he wins) = 9430.
Nadal : 9615(current) - 600(Rome 2011) + 90(Madrid 2012) = 9105.
325 points will be the difference. Which means Nadal has to get at least 325 points more than Roger in Rome.
-If Nadal wins, he gets 1000. Final is 600, nothing Fed can do.
-If Nadal loses in final, he gets 600. 360 SF points are enough for Federer to make sure the gap gets smaller by at most 240 points and he remains #2. Taking into account Fed's cakewalk draw up to SF, an early loss by Rogi is nothing Rafa can count on, so he needs to win.
-If Nadal loses in semi, he gets 360. still more than 325, but don't forget seeded players are right into Round 2, so if Federer loses to Berlocq (
) in R2, he gets 45. Difference is down to 315 and Federer is number 2 for RG.