Roger Federer put some pressure on Novak Djokovic on Sunday when he defeated Milos Raonic in his first round-robin match. But the Swiss maestro will need to do a lot more if he is to become the ATP’s year-end No. 1.

More London: Federer Gets Revenge on Raonic

Federer begins the World Tour finals 1,310 points behind Djokovic, but he can gain a net of 375 points at Davis Cup, because Djokovic will drop 150 form last year and Federer could gain 225 if he wins both of his singles matches in Lille AND Switzerland defeats France in the final.

Even if Federer experiences the best case scenario at Davis Cup, that still leaves him with 935 points to make up in London.

Here are how the London points are awarded:

200 for each round-robin win (600 possible)
400 for a semifinal victory
500 for a title

Federer earned 200 points today, but no matter how many points he earns in London (he could conceivably earn 500 if he wins the title without a loss), Djokovic can still win the title if he does the following:

IF Djokovic reaches the SF with a 3-0 RR record, he will be guaranteed No. 1 ranking at year-end regardless of Federer’s results in London and the Davis Cup final.

IF Djokovic goes 2-1 in RR play and does not progress beyond the SF, Federer will need to win the title undefeated (5-0) and win one live singles rubber in the Davis Cup final.

Federer has very thin margins to play with in London, but he is off to a great start with his win over Raonic. On Monday Djokovic, who has now won 27 consecutive indoor matches, will face Marin Cilic in the evening session. If Cilic pulls the upset, then things will get interesting…

Djokovic is bidding to claim the year-end No. 1 ranking for the third time in four years, while Federer is shooting for his sixth year-end No. 1 ranking. If Federer can make it, he’d be the oldest year-end No. 1 in the history of the ATP.