I never hear anyone talk about this fantasy matchup. I think it could potentially be a disaster for Alvarez. Has he ever faced anyone without that type of hand speed and angles? He already has a hard enough time with low output guys who have even just a little bit of footwork. I'm pretty sure Calzaghe could take his best shot, but I also think Canelo wouldnt even get that many clean shots off on him. I guess there's always the chance that Calzaghe gets caught while showboating, but I think he has a very underrated chin. I think it would be a nightmare scenario for Alvarez. I'm talking face mangled up, bleeding all over the ring, swiping at thin air....that kinda fight
Calzaghe would probably be favoured. With that being said, Joe was knocked down twice by right hands from Hopkins and Jones Jr, neither of whom were in their primes. And Canelo is a fantastic counter puncher. Great right hand, beautiful left hook. Those two punches work well vs left handers like Joe. And because Canelo has so much confidence in his head movement and chin, it would be hard for Calzaghe to deter him from attacking. Look at the way Canelo took away a slick southpaw like Saunders. Not that Billy Joe is in Calzaghe's league, but he did have slick movement and southpaw angles. Do i think Calzaghe has the speed and skill to outwork Canelo and win a decision? Yes. But easy? No. Canelo is a fantastic two fisted puncher and he hits harder than most of Joe's opponents. And Joe was not some defensive wizard like Toney - despite Calzaghe's speed, he was hittable. Calzaghe by close decision but Canelo will hurt him with some big shots.
I also remember Robin Reid catching him with flash overhand right time and time again. Calzaghe's chin looked very good on that occasion - but his defence not so much. Joe would probably edge with his workrate and output, but I certainly don't think it would be easy and I don't see him doing much damage in the process. In his prime, Canelo's defence was excellent. Great reflexes, ability to move his head without exposing his chin and always giving a threat of those powerful, explosive counters. Not an easy proposition.
Well I think Joe wins going away. Not a competitive bout on the scorecards and hard to see Canelo doing much except for little 20 second bursts. The rest of the time he gets peppered.
Canelo has shown questionable stamina in some of his more competitive fights as well, especially the Danny Jacobs one. If Canelo didn't take him out in the first 6 rounds, Calzaghe would test his conditioning like no other fighter had before. With the power and skill he has, Canelo would definitely have ways to win, but I don't feel like he would be able to withstand that output and mental pressure over the full 12 rounds. Tough fight but Calzaghe would edge it.
Canelo has a history of doing well against guys with less handspeed. Against Khan he looked clumsy and static until he managed to disintegrate Khan's eggshell chin. Saunders was outboxing him for most of their fight as well. Calzaghe has freak handspeed and extreme workrate. He'd be a serious problem for Canelo even if they were the same size, but they're not - Calzaghe is the naturally lengthier and bigger man. Canelo has a history of managing to figure out another guy's rhythm and then nuking them, so he might do that here too. But my best guess is that Calzaghe does a Bivol on him.
Not to say that Canelo is a stamina monster or anything like that, but it is important to note that Canelo had a knee injury during his camp for Jacobs and couldn't do much road-work. In fact, he said he did the least road-work for the Jacobs fight out of any of his world-title fights iirc. In his prime though, Canelo has come on strong late into tough fights before like against Mosley, Lara, or Cotto on top of scoring a handful of championship round stoppages. He's no Pacquiao or Armstrong but I do think his stamina can get a bit overly criticised.