It has long been said that defense wins championships in football, yet in today's high scoring NFL, the statement doesn't hold much water. Allow me to share with you some interesting numbers.
First and foremost, allow me to define a "good" defense. To me, a good defense is one that allows twenty points or less in a game. I am using this formula in my statistics.
Since the AFL/NFL merger in 1970, there have been forty-six AFC and NFC Championship games. In the forty-six AFC title games, the losing team scored twenty points or less in all but eight of the games played (that's 38/46). In the forty-six NFC title games, the losing team scored twenty points or less in all but ten of the games played (36/46). Combining the two numbers together, the losing team scored twenty points or less in seventy-four of the ninety-two games played, a percentage of .804
I realize that the offense has become more prevalent since the turn of the century, so I decided to look at the last sixteen AFC and NFC title games. In the thirty-two games played, the losing team scored twenty points or less in all but eight of those games, that's 24-32 and that's a percentage of .750
Pretty safe to say that defense does win championships...well 80% of the time...