Corbett still felt the Sullivan he fought would’ve beaten Jackson

By that point John L. had become an obese alcoholic, but it did seem like he had some of his old ability even at that stage. Jim was always pretty callous in his portrayal of Sullivan as an archaic brute throughout his career, so I doubt he’s motivated by bias when it comes to assessing John L.’s abilities. Corbett was also adamant in his appraisal of Jackson, more so than his appraisal of Sullivan, so I doubt his own prejudice has a role either.

Corbett said: "I tell you that no one can whip Sullivan who is not as fast as I am. I am not so sure that he wouldn’t whip Peter Jackson, for Peter’s style would suit him a good deal better than mine. Peter would go and shy with him, and no man can do that with any hope of success."