Both the NFL (football) and NBA (basketball) have their franchises (32 and 30 respectively) which draws younger players from colleges. These professional leagues are far superior to the amateur colleges.
MLB (baseball) which is currently engaged in sport suicide (boneheaded lockout) uses three-tiered minor league system to progress younger players from high school and college. Triple A is the highest while Single A the lowest. These teams develop talent and are also staffed with aging veterans (although that happens less and less), pro players on injury rehab assignments, and career minor leaguers. The NBA also has something similar, but the scope is less extensive.
While the idea of team (or franchise) relegation and promotion is intriguing it's all about the money here. While there are franchises or teams that hardly ever win a championship (Detroit Lions are perhaps the best example of never sniffing a Super Bowl in the NFL) the idea of them being sent is doubly unfair to me. They do try and have had great players but just haven't put it all together.
There is also roster size to consider in these discussions as the NFL has 53 players (11 on offense and 11 on defense), the NBA about 11 (5 starters), and MLB 25 (9 positions). The talent pool is noticeably between pro teams and colleges.
