Explained: How Rafael Nadal and Stefanos Tsitsipas can leapfrog Carlos Alcaraz for year-end World No. 1 spot at ATP Finals

The battle for the ATP year-end World No. 1 spot is now a three-horse race between Rafael Nadal, Carlos Alcaraz, and Stefanos Tsitsipas. The two Spaniards were clear favorites before the Paris Masters, but Tsitsipas has put himself in contention courtesy of a strong performance in Paris-Bercy this week.

As things stand, Alcaraz still holds a significant lead at the top of the ATP Rankings and thereby remains the favorite to retain the No. 1 spot, despite missing out on next week's ATP Finals. The 19-year-old currently holds 6,820 points (live rankings) to World No. 2 Nadal's 5,820 points. By reaching the Paris Masters semifinals, Tsitsipas has propelled himself to the third spot, just 470 points behind Nadal, with 5,350 ranking points.

Alcaraz will miss the ATP Finals after Saturday's announcement that an abdominal injury has forced him to withdraw ahead of his maiden appearance at the season-ending championship, meaning that the scenario for both Nadal and Tsitsipas is pretty straightforward.

The 22-time Grand Slam champion will clinch the year-end No. 1 spot by winning the 2022 ATP Finals as he will earn 1,500 points that will take him comfortably above Alcaraz in the rankings. The 36-year-old also has a chance to clinch the top spot if he loses in the final, provided he wins his first four matches and remains undefeated en route to the final. However, Nadal must ensure that he does not lose the final to an undefeated Tsitsipas, or he could end up losing the No. 1 ranking even by reaching the final undefeated.

In a scenario where the Spaniard remains undefeated throughout but loses in the final, he would earn 1,000 points at the end of the ATP Finals, which would put him at level points with Alcaraz. But he would then earn the top spot (provided he does not lose to an undefeated Tsitsipas in the final) by virtue of earning more combined points at the Grand Slams, Masters 1000 tournaments, and ATP Finals than Alcaraz.

For Tsitsipas, the third and final contender for the World No. 1 spot, the situation demands that he win the 2022 ATP Finals without losing a single match, which is the only way he can clinch the year-end top spot in the rankings.

Carlos Alcaraz draws another parallel with Rafael Nadal after ATP Finals 2022 withdrawal

Rolex Paris Masters - Day Five

Many of Carlos Alcaraz's achievements so far have greatly resembled those of his compatriot Rafael Nadal back in his early days as a pro tennis player. Those similarities continued after Alcaraz's withdrawal from the ATP Finals meant that, like his fellow Spaniard, he too will miss his maiden ATP Finals due to injury. Nadal missed the 2005 ATP Finals (then known as the Tennis Masters Cup) due to a foot injury.

The 22-time Major champion's Paris Masters campaign got off to a great start as he led Tommy Paul by a set and a break in their Round of 32 match before fatigue caught up with him and he lost in three sets. The former World No. 1 suggested that he is eager to play in the ATP Finals despite fitness issues and will now need to brush aside the Paris Masters loss as he bids for the year-end No. 1 spot for the sixth time in his career.