Alexander Zverev is close to securing the world number one ranking at the end of the year, with the upcoming Shanghai Masters potentially playing a crucial role. According to calculations released by the ATP on October 9, Zverev could be guaranteed the year-end top spot without even winning the tournament. A semifinal appearance in Shanghai would be enough for him to finish the year as the world's best tennis player. There are two possible paths for Zverev to achieve this goal. The first depends solely on his own performance: if he reaches the semifinals in Shanghai, he would be in a position where no other player could surpass him in the final rankings. However, he could also secure the top spot even if he doesn’t go that far in the tournament. For this to happen, both Carlos Alcaraz and Ben Shelton would need to be eliminated before the final rounds, regardless of which round they are knocked out in. In that case, Zverev would be guaranteed the year-end number one ranking even if he loses early in the tournament. Jannik Sinner, who has been Zverev’s main rival for the top spot, announced on Tuesday that he will not compete again in 2026 due to a knee injury. This decision has significantly improved Zverev’s chances, as he now holds an 810-point lead over Sinner, who cannot increase his points this season. Alcaraz is 4,200 points behind Zverev, and Shelton is even further back at 4,320 points. It is important to note that Sinner will still be ranked number one in the ATP rankings after the Shanghai tournament, regardless of its outcome. This guarantee applies only to the year-end ranking, not the weekly rankings. Zverev has already had a successful year, winning two Grand Slam titles at Roland-Garros and the US Open. He also holds the best win record on the ATP circuit with 58 victories before the Shanghai Masters.