Who cheated the most in sports?

Pete Rose bet on baseball games, but to the best of my knowledge it's never been proven that he actually rigged the results of any games. The infamous "Black Sox" who deliberately threw the 1919 World Series would have to be at least as bad if not worse by that measure.

Evander Holyfield .  He absolutely cheated and head butted Mike Tyson, and was known for doing it in other bouts,  but when he did it to TYSON,    Tyson got pissed off the ref didn't call it,  and bit his ear off. 

It was to prove that TWO can cheat, but only Tyson was punished. 

Holyfield was sneaky about it and tried to play it off like he wasn't cheating first. 

I'd go with Sammy Sosa and his corked bat.

In my opinion, it is Tom Brady.