Sullivan was about as shot as you can get when Corbett beat him. There is no reason to think that he would have replicated the result against a prime Sullivan, so that logic quickly collapses.
I would have to favor Tunney with his better all-around boxing skills. Boxing was a different sport in their respective eras, not as scientific in Sullivan's time, so a fair comparison may be difficult. But I don't think Sullivan would be an easy mark for anyone - even an old, ill-conditioned Sullivan lasted 21 rounds against a prime Corbett, so it would be a mistake to underestimate him. There again, Gene Tunney never underestimated an opponent - he would make a thorough study of Sullivan as Corbett did and come to the ring superbly conditioned and well-prepared. In a 15-rounder, I could see Tunney winning a comfortable decision.
Ruhlin was definitely the 2nd best heavyweight in the world before he faced Jeffries. Kilrain was probably the 2nd best heavyweight in the world before he faced Sullivan. It's just odd that a man with so few heavyweight fights can be ranked so highly. His best achievement at heavyweight is beating an old Jack Dempsey.
Well, Ruhlin was behind Jeffries and Fitzsimmons for sure, so that'd put him at 3 at the highest. For Kilrain, he was behind John L Sullivan, and Peter Jackson for sure, probably Frank Slavin too. I think you'd have a really hard time arguing Ruhlin, Sharkey or Kilrain had a better win than past it Dempsey.
For the time Ruhlin was the 2nd best, Fitzsimmons had retired, this was in 1901. Fitz would obviously make a comeback in 1902. I think Kilrain was the 2nd best in 1889, Peter Jackson and Frank Slavin were still in Australia. They would become top contenders 2 or 3 years after 1889. I think Tom Sharkey's win against a prime Corbett is just as creditable as a win over past it Dempsey. Ruhlin and Kilrain don't have a win that's as good as past it Dempsey, in fairness.
I don't think you can take much of anything from the fight between Corbett and Sharkey. The reports are all over the place, I've seen one that had Corbett comfortably ahead. It's pretty clear Corbett was doing better as it went on, and there was some suspicion the entire thing was fake.
You can't seriously believe that Sullivan was a really good boxer in his prime, it's common sense, he had no one to replicate or copy, most of the people he fought were sailors or 300lbs fat men or captains Every one back then stood leaning back and when they landed one punch they would clinch and when they threw combinations they looked sloppy, even Corbett was like this, why do you believe Sullivan would be any better? Also Sullivan was 33 when he fought Corbett, that is not washed Anyway, Tunney is a far more evolved and better version of Corbett, Sullivan would've had no idea of how to cut off the ring and would've been sloppy and Tunney would just be far too good
I've read reports of that fight that are the complete opposite of what you describe. I read a report that said Corbett was getting fatigued, and would've been stopped, if McVey wouldn't have jumped through the ropes.
John L could have even greater if they'd kept him out of the pub more! John L is on the loose, send for Muldoon! I'd probably take Gene on points, maybe a little too clever.
The reports are all over the map for sure. Like I said it's hard to take anything from it. Do you know which report that was?
That's not how Joe Gans, James Jeffries or Sam Langford fought. Besides, given all reports we have it's highly unlikely that Sullivan fought that way, because he fought out of the crouch.
In 1890 I'd pick Sullivan to slaughter Tunney. Take a prime Sullivan into the new rules era and Tunney is probably the favorite but for the first 3 rounds or so I'd be scared if I had money on Gene . I do know one thing for certain ,,no fight with John L. Sullivan would be easy.