'Sincaraz' heads for fitting final chapter of 2025

The battle is about to recommence.

Carlos Alcaraz emphasised it by using two emojis - a number one and a sword fight - in an Instagram post of him posing with Jannik Sinner after their pre-ATP Finals practice on Friday.

Whether Alcaraz or Sinner will finish as the year-end world number one is a key point of interest at this week's season-ending event in Turin.

Ending a long and gruelling season as the best player on the tour is a prestigious accolade, rewarding their brilliance and consistency over the previous 12 months.

Sinner retaining the title would be even more remarkable given the 24-year-old Italian did not play for three months, having been banned for failing two doping tests.

Spain's Alcaraz finally usurped his rival at the top of the rankings in September, ending Sinner's 65-week stint by winning the final Grand Slam of 2025 in New York.

Now the clear two-horse race goes to the last event of the season, with 22-year-old Alcaraz looking the favourite to win their duel.

"If Carlos plays really well there is no chance, it doesn't matter what my result is," said Sinner.

BBC Sport analyses the permutations for each player and who could potentially stop them. At the bottom of the page, you can vote for who you think will triumph in Turin.

For the second season in a row, 'Sincaraz' has been the absorbing narrative of the ATP Tour.

So it feels fitting the pair's battle for supremacy in 2025 - like all engrossing stories - will have a gripping final chapter.

Alcaraz goes into Turin in pole position, holding a lead of 1,050 points over Sinner when the latest rankings are released on Monday.

This is what each has to do over the next eight days to finish as the year-end number one:

Winning the title without losing a round-robin match earns 1,500 ranking points.

Players earn 200 points per round-robin match victory, 400 points for a semi-final win and 500 points for lifting the title.

"Ending as the number one has been an important goal for me since halfway through the year," said Alcaraz, who previously claimed the accolade in 2022.

The pair have dominated the men's game once again this year, sweeping all four Grand Slam titles between them for a second successive season and leading the regular tour by a considerable margin.

Sinner defended the Australian Open in January - his final tournament before being sidelined - and was beaten by Alcaraz in a classic French Open final on his return to major action.

A month later, the pair met again in the Wimbledon final, where Sinner demonstrated the quality of his mental strength to triumph and admirably bounce back from his Paris heartbreak.

The last stanza of their compelling Grand Slam trilogy took place in New York, with Alcaraz producing what he regarded as one of the finest performances of his career to ensure an even split of the four majors in 2025.

With the top two seeds kept apart in Thursday's draw, Alcaraz was put into the Jimmy Connors Group - where the spectre of Novak Djokovic loomed large.

However, seven-time champion Djokovic decided to withdraw from the Finals on Saturday, shortly after claiming his 101st tour-level title at the ATP 250 event in Athens.

Djokovic has recently moved to the Greek capital and played because of his strong emotional ties to the tournament, which was moved from Belgrade this year and is run by his younger brother Djordje.

The 24-time Grand Slam champion might be 38 and showing clear signs his powers are waning, but remains the player most capable of beating Alcaraz and Sinner - meaning the fourth seed's withdrawal can only benefit the Spaniard.

Italy's Lorenzo Musetti, whose loss to Djokovic in the Athens final denied him automatic qualification, ended up in the Finals anyway as a result of his opponent opting not to go to Turin.

The group is rounded out by last year's runner-up Taylor Fritz, who has cemented his place as a leading star this year, and the ultra-consistent Alex de Minaur.

Taylor Fritz, 28, United States

Seed: 6

Best ATP Finals performance: Runner-up (2024)

2025 titles: 2 (Stuttgart, Eastbourne)

2025 win-loss: 52-21

Alex de Minaur, 26, Australia

Seed: 7

Best ATP Finals performance: Group stage (2024)

2025 titles: 1 (Washington)

2025 win-loss: 55-21

Lorenzo Musetti, 23, Italy

Seed: 9

Best ATP Finals performance: Debut

2025 titles: 0

2025 win-loss: 44-20

Sinner might insist Alcaraz is the favourite to claim the year-end title, but the Italian's supremacy on indoor courts - coupled with Alcaraz's relative uncertainty in the conditions - means it is far from a foregone conclusion.

With his metronomic ball-striking thriving in the benign conditions, Sinner extended his winning streak indoor to 26 matches by lifting the recent Paris Masters title.

Winning the Finals last year without dropping a set also shows how he found the conditions in Turin to his liking.

But he has a tougher draw in terms of the seedings than Alcaraz.

German third seed Alexander Zverev and American fifth seed Ben Shelton were already locked into the Bjorn Borg Group when the draw was made, but Canada's Felix Auger-Aliassime faced an anxious wait for the eighth and final spot.

Auger-Aliassime, who made a late surge into the top eight by reaching the Paris final last month, arrived in Turin several days ago but knew he had to wait for Musetti's performance in Athens to seal their fate.

In the end, both Auger-Aliassime and Musetti will play after Djokovic pulled out.

Alexander Zverev, 28, Germany

Seed: 3

Best ATP Finals performance: Champion (2018, 2021)

2025 titles: 1 (Munich)

2025 win-loss: 54-23

Ben Shelton, 23, United States

Seed: 5

Best ATP Finals performance: Debut

2025 titles: 1 (Canada)

2025 win-loss: 40-21

Felix Auger-Aliassime, 25, Canada

Seed: 8

Best ATP Finals performance: Group stage (2022)

2025 titles: 3

2025 win-loss: 48-22