Dark Trade: Lost in Boxing by Donald McRae
This is a collection of pieces focussing mainly on James Toney, Roy Jones, Tyson (and others) when they were in their primes in the nineties. Basically, McRae is a journalist who followed various fighters around to glean long interviews from them regarding their lives and perspectives on the fight game. Special attention is paid in particular to Toney, with whom Macrae develops a long friendship during the course of researching and travelling with the fighter for his fights with Thornton, Jones, Griffin, etc. I found it an interesting read when I read it several years ago, but the one drawback I would point out is it's "middlebrowness"; that is, McRae brings a kind of middlebrow, middleclass perspective that I've found often infects the work of nonfighters who write about boxing, like Joyce Carol Oates. (He has a tendency, like Oates, to attempt to wax profound and lyrical about the savage beauty of boxing, especially about how boxing is a "metaphor" for the struggle of man at his most primal, and other pretentious exaggerations. These writers typically do not know much about the technicalities of boxing or the daily regimen of training and things like that, but view boxing from a distance, as a middle-class spectator would.)
Nevertheless, McRae was close enough to the principal personalities in the book to give us some interesting information about the habits of fighters and their idiosyncratic behaviours. (There is an amusing and somewhat touching scene where the author and a resurgent Toney discuss his humiliating loss to Jones while watching promotional videos and other buildup material for the fight. At one point, Toney nods approvingly at footage of himself announcing that he would kick Jones's ass and make him his bitch, etc.)
For those interested, there are also some chapters devoted to Naseem Hamed, de la Hoya, Rafael Ruelas, and Holyfield, though the author didn't manage to get as close to them as he did to Toney.
Another book by the same author (which I haven't read) is
Heroes without a Country
about Jesse Owens and Joe Louis.