Sor Rungvisai. He was involved in 2 matches against the P4P No. 1 fighter, beat him both times, once in the FOTY, the second he produced maybe the KOOTY.
Lomachenko/GGG/Joshua/Crawford/Rungvisai Could make a case for any one of those guys by the years end.
Rigo if he beats Lomachenko. Otherwise, my large short-list is Joshua (Wlad, Takam?) if he beats Takam impressively Ward (Kovalev) Eubank Jr (Quinlan, Abraham, Yildirim) Groves (Chudinov, Cox) Golovkin (Jacobs, Canelo Draw) Canelo (JCC Jr, GGG Draw) Saunders/Lemiuex winner (Lemiuex/Saunders, Monroe Jr/Stevens) Crawford (Indongo, Diaz) Horn (Pac, Funeka) Thurman (Garcia) and Spence Jr (Brook) both had one very good win, pity they weren't more active. Mikey Garcia (Zlaticanin, Broner) Lomachenko (Sosa Marriaga, Rigo?) if he beats Rigo Berchelt (Vargas, Miura) would've had a very good chance if he hadn't had to pull out vs Salido. Sor Rungvisai (Gonzalez x2) Who would you choose and who am I missing?
The short list should include Rungvisai, Loma/Rigo, GGG, Joshua and Mikey. Of course depending how Loma/Rigo plays out, how Joshua handles Takam and what Mikey does before year end.