He says the only man who knocked him out was Wlad. Briggs never fought Wlad, except on a jet ski. It's someone from Brooklyn....claims to be from Tyson's neighborhood. I could research this guy, but I'd rather just believe he's for real because he's an intelligent writer (which would seem to eliminate a HW boxer but that's a prejudice) and his stories ring true.
Klitschko hits harder than David Tua ? I don't know about that one.. Of course Its possible but Wow..
Foreman would knock Tyson all over the ring, he barely landed any clean shots on Holyfield. Foreman was more powerful than Tyson, deal with it.
He might be referring to sparring...You'd still get a good idea of how hard someone hits through that experience.