The U.S. Open began Monday in Queens and didn’t encounter too many bracket shakeups outside of Sloane Stephens getting upset, American Brandon Nakashima taking down the No. 15 seed and Maria Sakkari, the No. 9 women’s seed, retiring after her first set.

But as the final Grand Slam of the year progresses, there could be plenty of matches that end up capturing the most prominent storylines of the Open, including these eight:

1. Alcaraz-Sinner in the semifinals

Really, this head-to-head dates back to a 2019 Challenger Tour match in Alicante, Spain, where a 15-year-old Carlos Alcaraz defeated a 17-year-old Jannik Sinner in the Round of 64. The prize money for the winner was just over 6,000 euros. The stakes, at that stage of their careers, were low.