The research performed on this piece was very superficial. I expect better from NPR.
The fictional character "Rocky Balboa" is based upon Chuck Wepner. Don King decided to give a no-name a shot at the title and picked Wepner, known as the "Bayonne bleeder," that chance. Wepner lasted 15 rounds, exactly the number of rounds that Rocky lasted in the first movie against Apollo Creed. Wepner also knocked Muhammad Ali down, something that nobody was doing at that stage in Ali's career.
