Can Tunney beat Dempsey twice if their fight was scheduled for 15 rounds instead of 10! Im trying to research every history books on whats the deal and why their title fight was scheduled for only 10 rounds instead of the usual 15 or even 20 rounds in those times.

tunney is better, there is no other way to it.

No. Tunney was dominating Dempsey throughout both fights and it was Jack who didn't have his legs(There is however, the possibility of Dempsey always landing a lucky punch that gives an opening, like in the 7th fight)

A better question is if Tunney would have fared the same against a prime Dempsey who still had the foot-speed to counter Tunney's boxing style and didn't have the same level of ring-rust that he did when facing Tunney the first time.

To clarify, I meant that Tuney would still win I believe.

Tunney could stay sharp in the late rounds aswell, so i think he would still win.

Tunney would still win if the fight were 15 or 20 rounds. A prime or near prime Dempsey crushes him, says I.

tunney is better, there is no other way to it.

on the day!

Can Tunney beat Dempsey twice if their fight was scheduled for 15 rounds instead of 10! Im trying to research every history books on whats the deal and why their title fight was scheduled for only 10 rounds instead of the usual 15 or even 20 rounds in those times.

In short, no.

In the first fight, Dempsey either had the flu or some other stomache ailment or was poisoned and Tunney won easily, so 5 more rounds would not have helped Dempesy

In the second fight, Tunney damn near stopped Jack in the later rounds, after the long-count, so if it went another 5 rounds, odds are Tunney would have stopped Jack IMO.