Isn't he the guy that got knocked out by some German named Max? The same Max that would be a lightheavyweight today and get knocked out by Beterbiev?
I really enjoyed Louis vs. Schmeling The Fight of Our Generation by Lewis Erinberg. It is more like a great research book (would be perfect for college papers) but I really liked it.
Max is way more skilled and experienced than Beterbiev as well as being a much better puncher. Beterbiev lowballed his way out of fighting Sullivan Barrera and despite being 33 hasn't fought a good opponent yet. He's easily won of the biggest hypejobs in boxing today.
How does a pro boxer reach age 33 and not fight top shelf opponents? What is he waiting for? A carefully crafted invitation?
Callum Johnson is a solid fighter. Beterbiev beat Cloud and Campillo in his early fights. He's only became a world champion recently and hes's been ducked like the plague.