Okay, so I posted this in the before 1900 section because I was reading how originally, there was no professional baseball league in the 1860's, but a baseball association that was kind of like England's football association. Anyway, England's Football Association embraced professionalism eventually and worked within that system. Meanwhile in the USA, the Baseball Association, the National Association of Base Ball Players didn't survive professionalism, and the National League was eventually founded.
But what if the NABBP allowed professionalism and we had a Major league system with promotion and relegation? How would this effect baseball and other sports? Would it work in the U.S or fail because of distance (since scholars feel that the reason promotion and relegation worked in Europe was because the countries were smaller, and thus travel was easier and even small teams had decent fan bases, even when cities had multiple teams)