The NFL scouting combine will never turn a projected first-round pick into an undrafted free agent, or vice versa.

By this point in the careers of these prospects, their size has been established. So have their smarts. The film of their college performances is indelible, the basis of the evaluation for every team in the league. But over the four-day event at Lucas Oil Stadium, there are always players who help or hurt themselves, even if ever so slightly, when their speed, agility and strength is on display with the rest of their peers. Some even stand out by skipping certain drills.

Here are six notable performances from this year's combine in Indianapolis:

CONFOUNDING CLOWNEY: After a substandard 2013 season for South Carolina, defensive end Jadeveon Clowney has been dogged by questions about his work ethic and focus. But his blend of physical traits at 6-foot-5 and 265 pounds is so promising that he could still be the first pick in the draft. For him to fall out of the top five would be almost unfathomable.

This, then, was fitting. He ran the 40-yard dash in 4.53 seconds, the fastest at his position, but managed only 21 repetitions of the 225-pound bench press, fewer than several defensive backs and running backs and even one punter, Pat O'Donnell of Miami.

NFL Network analyst Mike Mayock summed up the enigma nicely.

"I already think I know what he is: he's the scariest, freakiest, physical specimen I've ever seen since I've been doing this," Mayock said. "However, that doesn't mean I'm saying he's the best defensive lineman in the draft or the best player in the draft because he worries me with some of the red flags."

GO JOHNNY GO: Johnny Manziel, like fellow top-tier quarterback prospect Teddy Bridgewater, opted not to throw for scouts over the weekend, preferring to wait until his pro day workout at Texas A&M. But while Bridgewater skipped the 40-yard dash, too, Manziel zipped right through it in 4.68 seconds. At 6 feet and less than 210 pounds, Manziel is smaller than the prototype for the position, but as he showed often in college he has the speed to make all kinds of excitement happen on the field.

SAM STRUGGLES: As the Southeastern Conference co-defensive player of the year for Missouri, Michael Sam has proven his pass-rushing prowess. He has made headlines for his quest to become the league's first openly gay player.

But ultimately, the biggest issue with Sam is he has the skills and the build that's caught between a defensive end in a 4-3 scheme and an outside linebacker in a 3-4 system. The "tweener" label could keep him as a mid-round pick at best.

Sam didn't boost his stock at the combine much, either. He ran the 40 in 4.91 seconds, hardly in Clowney's company. He also had the lowest vertical jump, 25 1/2 inches, and the second-fewest bench press reps, 17, among those at his position who participated.

FAST IS FAST: Kent State running back Dri Archer is a fringe prospect in this draft, at a mere 5-foot-8 and 175 pounds coming off an injury-affected senior season. He's considered a late-round pick, but Archer sure helped himself by running the 40-yard dash in 4.26 seconds, the best official time this year and a hair behind Chris Johnson's 2008 record of 4.24. Archer can also return kickoffs, which gives teams another value to consider.

NOT-SO-LITTLE BROTHER: Minnesota safety Brock Vereen is projected a late-round pick at best, but the younger brother of New England running back Shane Vereen ran a 4.47 in the 40, the 11th-fastest among all defensive players and second among safeties. Vereen also fared well in agility drills and led his position with 25 reps on the bench press.

Asked over the weekend about whether he wanted to be drafted higher than his brother - a long-shot goal because the Patriots took their Vereen in the second round in 2011 - Vereen brushed that off.

"I think the biggest part of me just wants to hit him," Vereen said. "I just can't wait until we meet on the field."

GILBERT GETS A BOOST: The depth of talent at so many positions this year might have left the cornerbacks a bit overlooked, but in this pass-driven league there is never a time when they've been more valuable. After Michigan State's Darqueze Dennard, the other guy at this position with a consensus first-round grade is Oklahoma State's Justin Gilbert. He ran the fastest 40 time among defensive players with a 4.37.

Courtesy of (AP)

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