because of how many more games are played now than were played in the past. It skews in favor of recent seasons when it was much easier to win 9 games because you play more games.

For example, in the '60s Nebraska usually played 10 or 11 games per year. In the 70s it increased to 12, in the late 90s it increased to 13, and now you even see the occasional 14-game season.

BYU is similar. During that same period, it has gone from 10 game seasons being the norm to 13 game seasons.