Carlos Alcaraz reached the semifinals of the ATP Finals with a perfect record during the group stage. This helped him clinch the year-end No. 1 ranking over Jannik Sinner, who was also in contention for the top spot.
Sinner won two Major titles and lost prior to the final of a tournament only twice this year, a streak that could continue at the ATP Finals. He also missed a good chunk of the season on account of his three-month doping ban.
However, Sinner still challenged Alcaraz for the top spot until the very end. Here's a quick rundown of their ranking points and how the race for the year-end No. 1 ranking unfolded over the season.
Carlos Alcaraz's heroics on clay helped him cross the initial benchmark set by Jannik Sinner

Neither player competed in any warm-up tournament before the Australian Open. Jannik Sinner was the defending champion in Melbourne. He mounted a successful title defense and earned 2,000 points for his efforts.
Carlos Alcaraz, on the other hand, bowed out in the quarterfinals, leaving with 400 points. Sinner's three-month doping ban came into force after the Australian Open. This gave the Spaniard the opportunity to make up some ground. A title in Rotterdam, worth 500 points, was a promising start.
However, Alcaraz was unable to sustain this momentum. He lost in the quarterfinals of the Qatar Open, made a semifinal exit from the Indian Wells Masters, and was knocked out in the second round of the Miami Open. These three results fetched him 510 points.
Despite being on the sidelines, Sinner remained in the lead at the end of the hardcourt swing with 2,000 points, while Alcaraz had 1,410.
The Spaniard hit the ground running on clay. Alcaraz won the Monte-Carlo Masters and followed it up with a runner-up finish at the Barcelona Open, before skipping the Madrid Open due to an injury. He added 1,330 points prior to the Italian Open, which also marked the return of Sinner to the tour. The two met in the final, with Alcaraz coming out on top.
They locked horns in the French Open final a few weeks later, and the Spaniard saved three championship points in an epic contest. He gained 4,330 points during the clay swing, with 2,000 coming from his triumph in Paris, bringing his yearly total to 5,740.
Alcaraz foiled Sinner's return to the tour, yet the Italian added 1,950 points on the red dirt. His points tally for the season after the French Open stood at 3,950. The scars from his French Open heartbreak were evident when he competed in his next tournament in Halle. He was the defending champion but went out in the second round.
Alcaraz, on the other hand, made a strong start to his grass swing with a title at Queen's Club. He added 500 points to his tally and was confident of a three-peat at Wimbledon. Sinner had other plans, though, and beat the Spaniard in the final to win his second Major of the year.
Sinner's victory at the All England Club took his points total for the year to 6,000, while Alcaraz remained ahead with 7,540. Both skipped the Canadian Open and met in the Cincinnati Open final upon their return to the tour. Alcaraz lifted the trophy after Sinner retired due to illness.
The duo's rivalry continued at the US Open, where Alcaraz beat Sinner in yet another final, bringing an end to the Italian's title defense. The Spaniard increased his points tally to 10,540, while the Italian trailed with 7,950.
Jannik Sinner almost caught up to Carlos Alcaraz but fell short in the end

Carlos Alcaraz continued his impressive run of form with a title at the Japan Open. However, an injury sustained during the tournament forced him to withdraw from the Shanghai Masters. Jannik Sinner, meanwhile, won the China Open and had an opportunity to cut down his rival's lead with a deep run in Shanghai.
However, Sinner couldn't capitalize on Alcaraz's absence in Shanghai. The brutal conditions forced him to retire during his third-round contest. The Asian swing concluded with Alcaraz having 11,040 points and Sinner on 8,500.
Sinner secured another 500 points with a title in Vienna. Alcaraz had the opportunity to claim the year-end No. 1 ranking at the Paris Masters but lost in the second round. The Italian made the most of this opening and won the title, along with the 1,000 points that come with it.
Nevertheless, Alcaraz held a commanding lead over Sinner entering the ATP Finals. The Spaniard had 11,050 points, while the Italian had 10,000 points. Alcaraz needed to win all three of his group stage matches in order to claim the year-end No. 1 ranking, regardless of Sinner's results.
Alcaraz did just that, finishing the season ranked No. 1 for the second time in his career, having first accomplished this feat in 2022. Sinner concluded the 2024 season on top and just missed out on repeating the feat this year.
Here's a detailed breakdown of their points tallies thus far in 2025:
Their final points tally for the 2025 season will be known in the coming days. If Alcaraz loses in the semifinals of the ATP Finals, then he will end the year with 11,650 points. If he wins the title, he will have 12,550 points; if he loses in the final, he will finish the year with 12,050 points.
Sinner could leave the ATP Finals with a maximum of 11,500 points if he wins the title. A runner-up finish will leave him with 11,000 points, and if he loses in the semifinals, he will end the year with 10,600 points.
This will be the first time two players will end the year with at least 10,000 ranking points since 2016. Andy Murray was the year-end No. 1 that year with 12,410 points, followed by Novak Djokovic in second place with 11,780 points.