The last few years, Novak Djokovic has challenged Federer at his home tournament in Basel. This year, he opted not to play. Let’s see how this impacts Federer’s chances at number 1.
Currently, Federer has 12165 points to Djokovic’s 11970 points for 195 point lead. However, Djokovic played last year and reached the semis. This year, those points will drop off. Federer won the tournament and earned 500 points.
Let’s remove both point earnings from Basel.
This would leave Federer with 11665 points to Djokovic’s 11790 points. Had Federer not played Basel, Djokovic would regain number 1. The difference between the two is 125 points. Federer needs to earn 130 points to stay ahead of Djokovic. This means Federer would need to reach the semifinals to gain one additional week. Should Federer win Basel, something that seems easier with only del Potro in the top ten competing, then he would have a 195 + 180 = 375 point lead heading into Paris. This is a pretty slim lead. Paris awards 1000 points to the winner and runner up gets 600 points. Should Djokovic lose in the semis or earlier, Federer could keep his lead even if he only wins a round or so. Federer can hope that Djokovic and Murray end up in the same half in Paris. Murray is too far behind to catch up at least in Paris.
This could create a race that goes all the way to London to decide who number 1 is. Right now, Djokovic has a pretty hefty lead, but Federer is playing this week and Djokovic isn’t, so Federer is making a play to finish number 1.