Paris Masters begins right after Basel gets over. Paris first round could be on 31st/1st which is only 2/3 days after the Basel final. At Basel, he has 4 3-set matches which will not be easy. I am actually worried Roger might get zapped out sometime during the Paris masters and might lose a match. Roger really needs to win Paris to have a reasonable chance to clinch YE-no. 1.
Consider this:
Final at Basel (300)
Win at Bercy (1000) and Nadal doesn't play Bercy.
That will leave Roger 660 points behind Nadal.
So, Roger will have much more than a puncher's chance to get no. 1 after WTF. There are some scenarios that allow it. In that case, the only scenario which won't allow Roger to succeed is Rafa reaches the final undefeated. One loss of Nadal and Roger will be in a position to make him pay for it.
And like I said, Roger doesn't even need to win Basel to make it happen. But if he wins Basel, then won't even need a loss from Nadal at WTF. He will have a chance till the end.
So, Roger does need a lot of help from Nadal. But, let's see.