As for the movies, though they may deal with the sport of boxing a really the story of this average man thrown into extraordinary circumstances. Rocky is a guy who may not have had the easiest life, but who makes the most of every opportunity. Rocky isn't the smartest guy, he isn't the most eloquent, but he still is the man whom we would all like to be, not because he's a boxer and the two-time heavyweight champion, but because he's a guy who always, no matter what, fights for what he thinks is right.
Within that basic outline though, the stories take on various forms. The first two tales are ones where Rocky has nothing and is just trying to scratch out a living, by the third he's rich and famous and looking to get back to top form, and by the fourth (and by far the silliest) installment in the series, Rocky is fighting for America against the Soviet Union. From there, the final two movies are both supposed to serve as something of a conclusion to the series. Rocky V actually returns John Avildsen, who directed the original (the others were all directed by Stallone) back to the helm, and shows Rocky trying to cope with being retired and losing his money. Rocky Balboa gives the ex-champ one last time to fight and help save boxing, exorcise his demons and to find a way to not go softly into that good night.
When the films focus on the small stories – the downtrodden Rocky; the Rocky just trying to first get a family, then keep his family – they are at their best. Essentially, the films work when Rocky is an underdog, not when he is a superhero. It may be fun to watch Rocky slug it out with the superhuman Ivan Drago in Rocky IV, but outside of atrociously overdone fights, the film has no power behind it, it has lost all that is essentially Rocky.
The fifth film actually acts as a mea culpa to Rocky IV, with Rocky no longer being allowed to fight in the ring and retiring… again. It's the story of how Rocky tries to keep boxing as pure as he remembers it by training a young up-and-comer who is, unfortunately seduced by the dark side of the sport. The film might actually have worked as a satisfying conclusion to the series except for the incredibly poor acting on Tommy Morrison's part – it's almost impossible to not cringe every time he speaks – and the franchise's dogged insistence on having a fight scene in every film. As Rocky can't box in the ring anymore, the climactic fight is a street brawl between Tommy and Rocky. For a series that has choreographed some brilliant boxing matches, it is an embarrassingly low point for the franchise. Whereas Rocky IV is purposefully over-the-top and silly, Rocky V attempts to scale back, to return the characters to their roots, but the story concocted to get them there is unsatisfying in the extreme.