20. Robert Griffin III
In a mirror universe, Griffin is still tearing up the NFC East with Washington. Sadly, that’s not the reality in our world because Griffin’s decline was stark. He was brilliant in 2012 after the Redskins drafted the former Baylor signal-caller. His performances earned him the Rookie of the Year Award as well as a place in the Pro Bowl. Meanwhile, Washington even made the postseason.

But this story doesn’t have a happy ending. Griffin tore multiple ligaments in his knee toward the end of his rookie season and his career never recovered. The team rushed him back and his stats plummeted. Eventually, Griffin lost his place as a starter and never bounced back. It’s crucial to protect quarterbacks and to give them time to recover. Otherwise, a generational talent will become a dud (via CBS Sports).