Speed and man-coverage ability.
Those are the two "boxes" every NFL scout wants to check off when grading out the cornerback position in the draft process.
Size, length, ball skills, toughness, etc.? Sure, those are boxes on the scouting report too, but you can't get into the mix as a Day 1 or early Day 2 selection in the NFL draft without the ability to run and stick to a receiver's hip down the field.
At 5'11", 193 pounds, Florida State's Ronald Darby doesn't have the NFL frame some teams are looking for outside of the numbers, but this guy can really run. He has the flexibility in his hips to change directions, and the skill set is there to challenge wideouts at the pro level.
"Darby has natural coverage skills," a scout told me. "He has good quickness to close, a fit for teams that play a lot of press-man. He's a top-60 player in the draft."
He could push his stock even higher than that if he's as impressive at his pro day Tuesday in Tallahassee, Florida, as he was when his speed and athletic measurables lit up the combine in February.
In Indianapolis, Darby posted an official 4.38 40 time. That's legit speed for the former track star out of Oxon Hill, Maryland. He also registered a 41.5" vertical jump, a 10'9" broad jump and a 6.94-second three-cone drill. Plenty of boxes to check off there.
Those are just numbers. I get it. The key to grading defensive backs is applying the testing to the game film and seeing what you get.
I've done that—and spoken to veteran scouts who have done the same—and the athleticism, speed and lateral movement mesh with his play on the field.
Take the vertical speed from Darby. Scouts want to see that time because it speaks to a prospect's ability to recover down the field. Cornerbacks get beaten in the league, and they have to show the catch-up speed to get back "in-phase" (on the hip in a position to play the ball). If a cornerback posts a time in the high 4.5 or low 4.6 range, scouts are going to grade him down. It is a true "stopwatch" position during testing.
Darby played to the "field side" (wide side off the field, away from the boundary) and wasn't contested consistently at Florida State, but he did show "on-the-ball production" (playing the ball while in-phase with the receiver) against Louisville, Notre Dame, Virginia and Oregon.
He didn't against Miami and wide receiver Phillip Dorsett. In that matchup, Darby gave up a post route for a score against Dorsett when he played from a "bail position" (open and sink) and allowed the receiver to gain separation at the top of the break.
A technique error led to the touchdown on that play, and there are more on the tape where Darby can rely too heavily on his physical tools. That's why scouts say he can get a little too "handsy" with receivers down the field, instead of maintaining his cushion and using his leverage.
But based on my experience, NFL defensive back coaches are going to be able to improve Darby's technique as the competition level rises during spring workouts and training camp. This is about repetition for Darby—or any rookie corner—once he steps onto the NFL stage. Get beaten and make corrections to apply the physical tools the position.
The same can be said for Darby's ability as a run defender on the edge. When you look at the tape, he isn't going to consistently set the edge of the formation like a Charles Tillman, and he's not going to drop running backs with violent blows. But don't tell me this guy can't tackle or doesn't want to tackle. I see plenty of examples where Darby gets the ball-carrier down in the open field.
Now, I don't think Darby is ever going to be a corner whom teams run away from, but he will tackle in the NFL. The coaches will make sure he can do that before he gets on the field.
Plus, to be honest, cornerbacks with man-coverage skills aren't drafted to tackle. That's just not reality. Instead, they are drafted to play press, stay square throughout the route and drive to the receiver—with speed.
When does Darby come off the board? Scouts expect a typical mid-first-round run on corners this year, with Michigan State's Trae Waynes, Wake Forest's Kevin Johnson and Washington's Marcus Peters going first. They see Darby in the "second phase" in the early second round when the real run starts at the position.
And when that expected run starts on Day 2 of the draft, take a look at the stopwatch times for the group. Speed and coverage ability. That's the ticket.
Seven-year NFL veteran Matt Bowen is an NFL National Lead Writer for Bleacher Report.