A great deal of it is mental, the ability to learn within the game, to perform at a high level - often with injury - and to weather the ups and downs of an emotional game through a 16-game season. Also, there is the willingness to prepare in the offseason, the film room, to learn the scheme and execute without a lot of repetition - that's football character.

I didn't play in the NFL, and I didn't play defensive line. But football, at the fundamental level, is football. It's about motivating people and getting the best out of them.

More often than not, you find players seeing something that they can help another player with or reinforce something the coaches are seeing. Veterans do that regularly with younger players.

After several years in the league, when a player becomes a vested veteran in the NFL, they play under a different set of rules. For instance, if you cut a vested veteran mid-season and they don't get picked up by another team, you owe them the remainder of their salary.

Jobs are hard to come by, so players are extremely motivated to do whatever it takes to keep their job.

Once you've proved to [the players] that you can help them become better players, you've earned their respect. They respect if you've achieved at a high level in this league, but that's not what they respect you for as a coach.

A great deal of it is mental, the ability to learn within the game, to perform at a high level - often with injury - and to weather the ups and downs of an emotional game through a 16-game season. Also, there is the willingness to prepare in the offseason, the film room, to learn the scheme and execute without a lot of repetition - that's football character.