Also, I think the real stat that matters would be how many times it has happened compared to the number of NFL seasons where that was possible from week 1 (which is basically every season (not sure of a time before divisions)). I'm 99% certain that would show how hard it is to beat a team 3 times in one season.
The stat used really just shows that if you swept a div opponent in the regular season, you are likely to beat them in the playoffs if you face each other.
Sweeping a div opponent good enough to reach the playoffs is no easy task, which is why beating a team 3 times in one season is hard. Just because the sweeping team usually wins the third time, that doesn't mean it's easy to beat a team thrice.
Last edited at 8/23/2017 2:49 pm