Jerries is getting whooped no matter how many rounds its set for. He doesn't have the defense/skill/power to mess with a prime Tuaman
Tua is an all time great powerpuncher and can nigh on decapitate a man. You need serious stick and move and an excellent defense to beat him Why would Tua lose beyond 12? Because Tua is as strong, quicker, more explosive, hits harder and is as fit as Jeffries, pre1920s boxers do not have super human stamina to fight over 12 rounds. The longer the fight goes on the more it suits Tua because he has more likelyhood of landing his powershots