Rocky has 8 movies total.
The series is better than the 8 Star Wars movies (maybe the 9th that is coming out will tip it back). Rocky V was a dud, but it had its redeeming moments with the fake Don King and the shady accountant who swindled all of Rock's money, which set the stage partially for the rest of the movies.
They blew the opportunity to turn that into an eternal gold mine. All they had to do--and this would save BIG on production costs, duplication, etc.--was have Rocky retire, then find Rambo on the streets, train him so he has a life "purpose". And there you have it. Title(s) would be something like "Rocky IX: Rambo 7: Requiem for Retribution". Oscar.