BoxRec

15 rounds

Sonny by KO 10

Liston in 1.

Sonny in 8.

Liston outjabs, and outmuscles him early. If it gets into the later rounds Johnson probably has the edge, and can begin to wear on Liston, but it'll be a hard road getting there, and even once he's there it's no guarantee he's going to get the win.

I favor Liston by KO around 8 or 9 rounds in a hard fought battle.

If it's a 20 rounder in 1909, Jack wins it with Liston quitting on his stool late.

If it's in 1963, Liston outpoints him.

Sonny Liston by knockout in 12.