Playing professional sports is a difficult job, and some great players take years to get settled in and reach their potential. Others, however, become instantly successful.

Each season, the top rookies in each league are honored. And every so often, one of these rookies puts together an incredible season that ranks among the best in pro sports — regardless of experience.

A terrific rookie season does not always translate to a great career. All-time greats like Eric Dickerson and Michael Jordan were instant superstars, winning their league’s rookie of the year award on their way to hall of fame careers.

Other players, like Dwight Gooden, were dominant early in their careers, but couldn’t maintain their high level of play. Of course, that does not diminish how impressive it is that these players could be so dominant against the greatest athletes in the world at a young age — in Gooden’s case age 19.

24/7 Wall St. reviewed historical statistics of the four major American sports leagues — the NFL, NHL, MLB, and NBA — on the Sports Reference family of sites to determine the greatest rookies of all time.

Click here to see the greatest rookies of all time.
Click here to see our methodology.