On Tuesday afternoon, Jannik Sinner said that him claiming World No. 1 spot again before the end of the year was "impossible", and he would focus on the next season. Hours later, Carlos Alcaraz lost in second round to Cameron Norrie. Would he still have said that knowing that Alcaraz will leave Paris empty handed (and dropping 90 points from last year - Alcaraz only "wins" 10 points by being seeded and missing round 1)?
The truth is that Jannik Sinner now has a clear shot at claiming World No. 1 title, at least for two weeks. The match is simple: on Monday, Alcaraz will drop to 11,250 points. If Sinner wins the tournament in Paris (in what would be his only Masters title of the year), Sinner would have 11,500 points.
Anything other than that would still mean that Alcaraz remains World No. 1 next week, when the rankings are updated. If Sinner were to lose the final, he would earn 640 points, ending the year with 11,150 points, only 100 points behind Alcaraz. Those amounts are the maximum numbers of points Sinner can end the year with.
What can happen in ATP Finals?
The good news for Alcaraz is that the maximum number of points that Sinner can end with this year is 11,500, from a title in Paris. Second best number would be 11,150 points as finalist in Paris.
So, even if Sinner wins in Paris and loses World No. 1 for two weeks, Alcaraz could still retake it in the ATP Finals, even if Sinner wins them. To do that, however, he needs to win at least three matches (in the case that Sinner wins everything, of course).
In the ATP season finale between November 9 and 16, Sinner could only drop or maintain points, as he won all five matches last year (the three group stage matches, which give 200 points each, semi-finals which give 400 points, and final, 500 points), to earn the top prize of 1,500 points. Last year, Alcaraz only won one group stage match, which translates to 200 points he needs to defend, and at least 400 points to go from his 11,250 points after Paris to 11,650, against potentially 11,500 points from Sinner.
This means that, in the case Sinner wins Paris Masters, Alcaraz would need to win at least three matches in ATP Finals: the three group stage matches, or two group stage matches and the semi-final. Despite Alcaraz defeat, he still has the upper hand, but he can't relax and needs to improve from his 54 unforced errors yesterday. The race is still on.