Ask most football experts what made Warren Sapp the best three-technique defensive tackle in the history of the game and they're likely to tell you it was his speed, or his quickness, or his agility - or a combination of the three.
Ask Derrick Brooks and he'll tell you it was Sapp's vision.
When lined up in his three-point stance, Sapp saw the game from a point of view different than almost any player on the field. His ability to interpret what he saw was a big part of what made Sapp, and even Brooks, special.
"From four feet down, there was no better set of eyes," Brooks said. "No better eyes, no better instincts. That's what he brought, whether it was looking at an offensive lineman's stance, a protection or a tendency. And that's how we communicated.
"If he saw something, we had signals. If he saw a guard was pulling, we had a signal. If I saw a protection change or something that he couldn't see because he's four feet down, we had words. We would alert each other.
"I won't share what they were. It's not meant for anybody else. They were just words or touches. He'd turn around and he'd be waiting on my eyes. And once he got into his stance, he'd talk to me. That's just how we did it."
And how, in a noisy stadium, could Brooks know he was hearing Sapp and not someone else?
"I know his voice. It was distinctive."
Everyone loves a comparison. By the time Sapp began making a name for himself at the University of Miami, Hurricanes fans were comparing him to Cortez Kennedy.
While leading the Canes to a national title in 1989, Kennedy set the standard by which all defensive tackles after him were gauged. The man who coached both, though, says there is no comparison.
"He was just the opposite of Cortez," former Canes coach Dennis Erickson said. "Cortez was a grinder, whereas Warren was just so athletic. He would just run through gaps and split sides.
"I don't know that there have been many players that dominated the football game at that particular position like he did. He just created havoc with the way he played. He got up the field. He was such a great athlete for that position. I don't know that I ever saw him get blocked to be honest with you in our time together at Miami."
The stuff of nightmares
With his ability to chase down running backs and terrorize quarterbacks, Sapp haunted offensive coordinators.
He forced changes to game plans few had ever considered before.
"I don't think there's any question about it, he was the prototype three-technique,'' said Brad Childress, who was forced by Sapp to change innumerable blocking schemes and game plans when he served as the offensive coordinator of the Philadelphia Eagles in the late 1990s and early 2000s.
"I still have real clear recollections of him chasing (Eagles quarterback) Donovan McNabb all over Veterans Stadium. He was a great player. And you had to account for him because the three-technique drives that defense the Bucs played then.
"And there's no question that he drove it for them. He had the keys."