Currently, Djokovic sits at the top of the pile after overtaking Alcaraz at the US Open. Not only did Djokovic reclaim the ATP No. 1 ranking, but he would also dethrone the Spaniard in the ATP Race, which factors points earned during the course of the season.
But Djokovic elected to give this year's Asian swing amiss, and that will come at a cost, as Alcaraz has a clear path to the top spot in the race. The 20-year-old added 180 points from his semifinal run at the China Open last week, cutting Djokovic's lead to 590 points.
What Alcaraz needs to do to overtake Djokovic in Shanghai:
The Spaniard is competing at the Shanghai Masters, which had a midweek start this past week. Alcaraz secured his spot in the round of 16 with a battling victory over Dan Evans. That guaranteed him 90 points at this tournament, truncating Djokovic's lead to 500 points.
The bare minimum Alcaraz needs to eclipse Djokovic in the race this week is to attain a runner-up finish in Shanghai. Djokovic has 8,945 points in this year's race (he can't add to his total until Paris-Bercy). Alcaraz has 8,445 points following his third-round win. He can add 510 points between now and the final in Shanghai.
In the event Alcaraz reaches the final (which looks likely), he'll own 8,955 points, which would be a marginal lead of 10 points over Djokovic. And if Alcaraz went on to win his first title on Chinese soil this week, he'll have 9,355 points, which would see him lead the race by 410 points.
Considering that Alcaraz is playing at the Swiss Indoors in a couple of weeks, he can add to his lead, potentially stretching it to 910 points (can win a maximum of 500 points in Basel). Obviously, these are all but the possible scenarios that could unfold this month.
Alcaraz still has to win his matches. We've seen the top seeds come crashing down at the Shanghai Masters and Alcaraz didn't have an easier time subduing Evans in his last match. And the tests will get harder from this stage, starting with a tricky fourth-round match against Grigor Dimitrov.