nadal has 6690 points while Ferrer has 6505 points.The difference is 185 points.
Since Ferrer can't add any more 250 tournament results to his countable results in the beginning of the year and andal is only defending 90 points from doha Ferrer can't overtake nadal for the 4th place.
Are my calculations correct?
As for the AO nadal is defending final points and ferrer quarters points. So ferrer has reaching the quarters and nadal losing in the semis or before would be enough for ferrer to rise to #4?
Yes. Nadal is also defending a nice amount before RG. Ferrer having the #4 seed for the French Open would be massive.