Jannik Sinner and Carlos Alcaraz are poised to add another entry into their rapidly developing rivalry when the ATP Finals open Sunday without any members of the Big Three for the first time in nearly a quarter century. The top-ranked Sinner and No. 3 Alcaraz evenly split the year’s Grand Slam titles between them with two apiece and it would be fitting if the pair meet again in Turin. And since Alcaraz was overtaken by Alexander Zverev in the rankings this week, the Spaniard could be placed in the same round-robin group as Sinner.