It's quite simple, Golovkin and Kovalev are more accomplished fighters than they are. Golovkin debuted as a pro at an older age, even if Canelo would've fought him right after winning the title against Cotto, Golovkin would have been 34. Now lets look at when Canelo actually did fight him, he was a whopping.... 35 lol. Don't forget that Canelo was in his second weight class, having moved up from 154. And for Kovalev he was in his fourth weight class, standing at just 5'7'' fighting the highest rated light heavyweight.