[Double Barrel]

Lots of coaches in NFL history have played their cards close to their chest and kept certain plays out of rotation until later in the season.

I rember seeing Bill Belichick talk about Bill Walsh and Tom Landry planning things like this, which he does, as well.

It's a simple concept. Don't show more than you need to show. If you don't need to reveal plays to beat lesser opponents that you are dominating, why do it? It's a tactical advantage to always keep something up your sleeve.