Alvarez is an accurate, smart puncher with good - not great - power. I think the belief that he has great power comes from the placement of his shots: how he sets them up, how he hides them ones that have power on them amongst ones that don't. Remember the old cliche: it's the punch you don't see coming that hurts the most.
The Chavez Jr. fight is interesting because he is such a big guy, and if properly trained, he can be a nuisance for a lot of people. He is there to be hit, but when he does show up - as opposed to most of his performances which have been rather curious ones these past fives years - he hides well behind his gloves and arms and keeps them pressure on you, mixing up his shots and not giving you much time to think. Canelo meanwhile, doesn't have amazing footwork (I know, people may not like the sound of that, but it's true), so he will have Junior in his face until Junior is stopped, or the final bell goes. At the same time, Canelo likes it when his opponents come to him. This is, of course, best case scenario for Chavez who has the capacity to be the proverbial turd in the punch bowl (something I think he probably doesn't mind being A LOT lol).
This, I believe is a reconaissance fight in the sense that it will give Alvarez a taste of a big pressure guy that can take a punch. If he can get past Chavez with few problems, he'll feel better about the GGG fight.
