They want to see strength, flexibility, hand placement, leverage, athleticism. And at least one team wants to know how many uses for a paper clip Michigan's Taylor Lewan can provide in a minute.
"I came up with a baker's dozen, probably," Lewan said at the NFL Scouting Combine in Indianapolis. "I was still going when the minute was up."
Evaluating Lewan's pro potential is best served analyzing the video clips.
The 6-foot-7, 309-pounder excelled at Michigan, earning consecutive Big Ten Offensive Lineman of the Year honors. Lewan – a converted defensive lineman in high school – started 48 games at left tackle for the Wolverines.
Despite being considered a first-round talent as a junior, Lewan returned to school for his senior year to further polish his game.
"That was a gamble, absolutely," Lewan said. "I wanted to be with my teammates for one more year.
"I think my fundamentals and techniques in pass protection and run blocking have gotten tremendously better."
Lewan is considered a virtual lock to be selected in the first round. But as far as offensive tackles are concerned, he ranks third behind Auburn's Greg Robinson and Texas A&M's Jake Matthews according to most draft pundits.
"Absolutely (that motivates me). Every single day when you wake up and you are in a competition and you are second-best or third-best, that should be the main motivating factor," Lewan said in an interview on the NFL Network. "When I wake up in the morning, I don't want to be the second or third-best offensive tackle. I want to be the best offensive tackle – not just now in college going to the draft but throughout my career I want to be the best in the NFL as well."
NFL teams applaud Lewan's talent and his relentless motor, and at least one team was likely impressed with his paper clip creativity. But some serious character questions were asked of Lewan at the combine – questions about his role in an incident following Michigan's loss to Ohio State late last season.
"I wasn't in any fight. I was actually breaking something up," Lewan said. "Some guy said I slugged him. That's not who I am off the field. It's not the kind of person I am."
Lewan is facing three assault charges, but he is confident his draft stock will not be affected.
"I've sat down with all the teams interested in me and explained the whole situation," Lewan said. "I think this will be resolved in a positive fashion."