Early-entry QBs don't have great history

TAMPA, Fla. -- Fans are clamoring for the Tampa Bay Buccaneers to take either Jameis Winston or Marcus Mariota with the first pick in this year's NFL draft.

But the numbers suggest that might not be such a good idea. Winston has declared himself eligible to enter the draft early. Mariota, who has a year of eligibility left, has until Thursday to put himself in the draft.

History has shown that early entrants don't guarantee success.

ESPN Stats & Information's Zach Mariner did research comparing quarterbacks who entered the draft early compared to those who used up their college eligibility. The difference in terms of success is dramatic.

Since the 1970 AFL-NFL merger, 20 quarterbacks have been taken with the No. 1 overall pick. Ten of them were seniors. The other 10 were early entrants.

The seniors have combined for a .555 winning percentage, 58 postseason games and 19 Super Bowl appearances. The early entrants have a combined .478 winning percentage, 17 postseason appearances and one Super Bowl appearance (Drew Bledsoe).

The list of seniors is highlighted by Terry Bradshaw, Jim Plunkett, John Elway, Troy Aikman, Peyton Manning and Eli Manning. All reached multiple Super Bowls.

The list of early entrants includes busts such as Jeff George, Tim Couch and JaMarcus Russell. But it should be noted that some recent early entrants have had success. Andrew Luck, Cam Newton and Matthew Stafford all led their teams to the playoffs this season.