16. Alex Rodriguez
We all know what happened at the end of Rodriguez’s career. However, the beginning of it wasn’t too great either. He was very average for his first couple of years, except, of course, for the fact he was only the third 18-year-old shortstop in Major League Baseball (MLB) since 1900.
That’s a nice stat, but the truth was that he didn’t do much in his rookie year. But he did evolve into a three-time American League MVP and five-time American League Home Run Champion. Of course, PED use destroyed his legacy, so we’ll never really know how good he was.