Determining early entrants' success

A record 65 non-seniors have declared for the 2012 NFL draft, including Mel Kiper Jr.'s top six prospects. Kiper has 18 early entrants projected as first-round draft picks, which would surpass the previous high of 17 in 2010.

More and more players are leaving school early to enter the draft every year, but not everyone believes that this is the best decision for the players involved.

NFL draft consultant Gil Brandt is among the skeptical: "I think in a lot of cases guys that are coming out, it's a mistake," Brandt said. "The people who stay in school and finish up seem to have a better chance of succeeding for a longer period in the National Football League."

Is Brandt's point valid? Do early entrants struggle to adjust to the more physical play in the NFL? Do early entrants fare better at certain positions?

ESPN Stats & Information set out to determine whether leaving college early for the NFL draft hinders or helps a player's chances of NFL success. All players selected in the first two rounds of the NFL draft since 2000 were included in the study. The results are broken down by draft status, longevity, career success and rookie impact.

Players who leave early for the draft are selected in the first two rounds at a higher rate than those who stay in school for four years.

Since 2000, of all players drafted, those who entered early were selected in the first two rounds 58.7 percent of the time. Conversely, those players drafted after their senior seasons were selected in the first two rounds just 19.9 percent of the time.

This makes sense, because the players who leave early often are top talents. The majority of players who leave early have a first- or second-round grade, according to ESPN draft analyst Todd McShay. Entering the draft makes sense financially and professionally.

In the 2012 draft, 33 of the 65 underclassmen are graded as first- or second-round prospects, according to McShay's seven-tier breakdown.

Being drafted high, however, doesn't always lead to NFL success or longevity.

Senior entrants average 5.5 more starts in their careers than their non-senior counterparts. Growth during the senior year might lead to longer careers. "The four-year player generally enters the league more mature -- mentally and physically," McShay said.

Linebackers benefit the most from the extra year in school; they start almost a full season more than linebackers who left early.

Tight ends who entered the draft early not only had the longest careers of all positions, they also averaged more than half a season longer than tight ends who did not come out early.

Running backs who stayed in college four years played more than half a season longer than running backs who left early. The extra wear and tear of an additional season in college did not negatively affect the length of their careers, as many would expect.

Of players drafted in the first two rounds since 2000, the ones who entered the draft early made the Pro Bowl at a slightly higher rate than those who stayed four years (28.4 percent versus 21.9).

The players' success was highly dependent upon position. Tight ends, defensive backs and quarterbacks who entered the draft early were the most successful, making the Pro Bowl at much higher rates than their counterparts who didn't enter the draft early.

Of the 17 non-senior tight ends drafted in the first two rounds since 2000, 10 have made the Pro Bowl, including All-Pros Todd Heap, Jeremy Shockey, Dallas Clark and Rob Gronkowski. Only two of 17 tight ends drafted in the first two rounds who did not leave early made the Pro Bowl.

Unlike tight ends, wide receivers appear to benefit most from extra time in college. Wide receivers who stayed four years averaged 467 more yards in their careers and made the Pro Bowl at a higher rate than those who came out early.

McShay noted the difference between college and the NFL: "Wide receivers rarely face complex coverage in college and rarely get pressed at the line by adept cornerbacks, so their transition to the NFL tends to be among the toughest of any position."

Troy Williamson is an example of a receiver who might have benefited from an extra year in college. He was selected seventh overall in 2005 but started only 24 games in five seasons and scored four touchdowns with the Vikings and Jaguars before being released.

Across all positions, players who left early tended to have better numbers in their rookie seasons than players who stayed all four years.

Wide receivers who left school early and were drafted in the first two rounds generally had more successful rookie seasons, averaging almost eight more catches and 123 more receiving yards than those who stayed four years. Over their careers, however, the wide receivers who stayed in college for four years averaged 35 more catches, 467 more receiving yards and 3.5 more touchdowns than the early entrants.

For example, Michael Clayton left LSU a year early and totaled 80 receptions for 1,193 yards and seven touchdowns during his rookie season in 2004. In the seven seasons since, Clayton has just 143 receptions, 1,762 yards and three touchdowns.

On the other end of the spectrum is Thomas Jones, who played all four years at Virginia. In general, running backs who played four years rushed for more yards and touchdowns over their careers than those who left early, but averaged 120 fewer rushing yards in their rookie seasons than early entrants. Jones fits into this trend; he carried the ball 112 times for just 373 yards in his rookie season but went on to rush for more than 10,000 yards in his career.

Offensive and defensive linemen produce similar statistics regardless of when they enter the draft.

Given the record number of underclassmen projected to be drafted, teams must evaluate whether a player has the right mix of experience and natural talent to succeed in the NFL.