Too bad there isn't a combine drill that measures heart, passion and how a young man will react to the pressure, the riches and the pervasive culture of entitlement heaped upon professional athletes. Until then, we're all pretty much throwing darts in the dark when it comes to pinpointing potential NFL success or failure for even the top college prospects. Here are five players who appear to be safe picks high in the draft and five who appear to be not so safe:

SAFE PICKS

1 Amari Cooper • WR, Alabama

Why he's safe: It's always scary to put a receiver on this list. But Cooper sure seems to have it all, minus the cancerous elite WR 'tude. First, he was tremendously productive at the highest level of college football. Beyond that, he has 4.4 speed, long arms, a competitive nature and already is a polished route runner.

2 Leonard Williams • DE, Southern California

Why he's safe: He's a gifted 6-4, 303-pounder with position and scheme flexibility. Considered by many to be the best player in the draft, he could fall to No. 3, which would be the best thing that's happened to Jacksonville in a very long time.

3 Cameron Erving • C, Florida State

Why he's safe: This isn't a bad year to be near the bottom of the first round if you're a team that needs help on the offensive line. Erving switched from left tackle to center and actually increased his draft value. He's 6-5, 313 pounds and has the build and talent to play anywhere on the line.

4 Andrus Peat • OT, Stanford

Why he's safe: The sense is he's a top-10 talent who will go near the bottom of the first round. Has the size and position flexibility to start immediately at guard and transition to either tackle position eventually.

5 Dante Fowler Jr. • DE, Florida

Why he's safe: Another flexible player who was productive in many different roles. Combine success helped confirm his potential as a standout pass rusher.

NOT-SO-SAFE PICKS

1 Jameis Winston • QB, Florida State

Why he's not so safe: Too immature and has too much off-the-field character baggage to be handing him the keys to the franchise as the No. 1 overall pick. The amount of time needed to untangle the potential mess he'd create isn't worth the risk. Trade down and wish him the best of luck.

2 Marcus Mariota • QB, Oregon

Why he's not so safe: Even if Tennessee doesn't want him, the sense is a team will panic and trade up to No. 2 so it can take him. Teams without quarterbacks in today's game are justified when they keep swinging until they find one. But the cost of trading up for Mariota is too risky. He could take time to develop into an NFL quarterback. And anyone who is a project quarterback isn't worth taking this high.

3 Breshad Perriman WR, Central Florida

Why he's not so safe: He sounds like the 2015 version of Troy Williamson. A player who rocketed up draft boards based on his 40-yard dashes. Perriman's production was just OK, and he had issues with drops (sound familiar?). But he runs a 4.24 and a 4.27 and suddenly he's a top-10 pick? No thanks.

4 Dorial Green-Beckham WR, Missouri

Why he's not so safe: He has tremendous size and speed, but his Knucklehead Meter reading trumps his physical skills and upside. He's completely untrustworthy after multiple arrests, his dismissal from Missouri and having to sit out last season.

5 Todd Gurley • RB, Georgia

Why he's not so safe: There's nothing that would make me use a first-round pick on a running back coming off a torn ACL. Nothing.