Again, the tournament did just get really interesting.
Novak - In his own category. The big question is whether, at 39, he can make it through against guys 1-2 decades younger. He's the name to beat, and a fun fact is that he's won more GS matches this year than anyone else. But...he's old. If he makes it through to the semis, he's got to be the favorite, but he could also be taken out in the next round or two.
Zverev - He should be the new favorite, but how can we not doubt that he'll find a way to blow this? He should zoom through the next two matches (Halys, then Khachanov or de Jong) and if Jodar cools down, he could have an easy QF.
Veteran darkhorses - Auger-Aliassime, Ruud, Paul, Rublev, De Minaur, Khachanov. These guys have pretty much been written off for Slams, but one could sneak through.
Young Bloods - Mensik, Tien, Jodar, Fonseca, Kouame...lots of talent here, but also hard to see anyone of these guys winning a Slam. I mean, Jodar just played his first ATP match earlier this year; Kouame is 17, and a young 17 (March). I wouldn't be suprised if the eventual winner comes from the Fonzie vs Novak match...if Joao beats Novak, he might get that boost he's been needing for things to come together for him.
Clay guys/journeymen - Borges, Dos Cerundolo, Cobolli, Tirante, Tabilo, Carreno Busta, etc. Very unlikely for the eventual winner to come from here, but all of them should look to players like Gaston Gaudio and Albert Costa to remind them of surprise Roland Garros champs.