According to a Wall Street Journal study of four recent broadcasts, and similar estimates by researchers, the average amount of time the ball is in play on the field during an NFL game is about 11 minutes.
In other words, if you tally up everything that happens between the time the ball is snapped and the play is whistled dead by the officials, there's barely enough time to prepare a hard-boiled egg. In fact, the average telecast devotes 56% more time to showing replays.
The most surprising finding of The Journal's study—that the average game has just 10 minutes and 43 seconds of actual playing time—has been corroborated by other researchers.
To my mind that's comparable to a geriatric tennis match! Why would I want to watch that? I can't even play tennis any more....
But I place a lot of hope in evolution!