The NFL season used to start with the Super Bowl champs playing the best incoming players from college!
It was known as the Chicago Charities College All-Star game, and it was a preseason game played from 1934 to 1976 before the start of each year's NFL season. The game would match the Super Bowl champs with a select team of star college seniors that had just graduated and were about to enter into the NFL.
As the name implies, the games were played in Chicago and they were usually pretty well attended, with an average north of 60,000 per game. In case you're wondering,the 42 games were pretty lopsided in favor of the NFL: 31 were won by the reigning champs, 9 were won by the college kids and 2 more were ties.