During the 2011 NFL preseason, Jon Gruden was curious.
Then an analyst for (network), Gruden was watching the Indianapolis Colts practice, and he noticed that their backups seldom saw the field. More specifically, Peyton Manning never really subbed out.
It was understandable considering that the legendary QB had never missed a game in 11 years up to that point. But preseason practice is normally a time where the reserves on both sides of the ball participate more than they will during the season.
Gruden walked up to then-offensive coordinator Tom Moore looking for an answer. He got one.