I’ve seen nothing that convinces me that Jeffries was any more than George Chuvalo. A 6’ or 6’1” , very strong, thick, iron chinned , well conditioned bull fighting in 1900. Again, from what I’ve seen. Liston was one of the all time greatest in 58 through 60 w a huge reach, strength, boxing skill, an amazing jab and devastating power. Unless Jeff’s chin was for real he’d lose early. Otherwise stopped likely on cuts at some point.
IMHO, a prime Jeffries could hang in there with Sonny. Liston, definitely not used to 20 rounds of fighting, and not exactly known for having great stamina, would tire. Then Jim would come on and get the stoppage. (As Janitor said, it could depend on which Jeffries showed up, as a pressure fighter would definitely be at a disadvantage against Sonny early on. I'm assuming Jeffries does the smart thing, trains accordingly, and shows up with the correct style to beat Sonny.)
Jeffries was super tough and regarded very highly by historians and other fighters. Gets remembered mainly for the Jack Johnson fight but his previous fights don't get recalled as much, he fought some serious opponents. As mentioned above, wonder how Sonny would be in the later rounds.
Jeffries really doesn't look suited to fighting a more modern style He was undersized compared to Sonny and his clinch heavy style would be a detriment in this fight. I also don't see where the widely held belief of his defensive skills come from. Nothing I've seen shows me this. Really don't favour Jefffies here I do feel compelled to note most of the footage existing today is the FOTC fight against Johnson which he became unretired for so it's fair to assume it's not a fair representation. I've seen other snippets where his hands look extremely low and he holds his chin at a very inviting manner.
Jeffries at his best is estimated to have fought from 210Ibs to 220Ibs, which Liston was within when he fought Folley, Machen, Patterson, and Ali. They were also roughly the same height. How is Jeffries undersized against Liston?
To be fair, I can't see how anyone who held their hands low could compete with Liston This content is protected
Liston would have a large reach advantage and would have 5-10 pounds on average, usually in and around 220-225 fight night. JJ was 215 on average I believe as you mentioned. Not astronomical but factor in Liston's strength and JJ would be the smaller man in the clinches like I said