Another oddity about Zverev's season. If he wins this match, he'll have two Slam titles this year but no other titles. Even Rafa in 2022--which was one of the weakest two-Slam seasons of the Open Era--won a 500 and a 250.
There's still a lot of tennis for Sascha to play, though: two 500s, two Masters, and the Tour Final, plus a sprinkling of 250s. But if Sinner comes back healthy in Asia, Sascha is going to have to earn the YE #1 ranking. Sort of a nice dramatic element to the end of the year, and even if his two Slam titles were relatively easy, the YE1 probably won't be.