Yes, when athletes choose to turn pro before graduating, they will end up dropping out of college early. As studies show, average around no more than 10% of total college athletes are able to turn pro. Most athletes may take 4-5 years because if an athlete choose to redshirt than they save a extra year of eligibility to compete which means their studies must also be extended for a year.

I believe the true statistic of the proportion of college athletes that go pro is actually closer to 1% (Professional baseball is an outlier as apparently around 9% go pro… crazy). This is also saying that “going pro” means going to the absolute most distinguished league of that sport, for example the NFL instead of Canadian Football League or the NBA not the development league.