For me, some of the strongest evidence that the NFL isn't rigged (besides the obvious) lies in the outcome of their 100th season.
Coming down the stretch, it looked like we were headed for a Steelers-49ers Super Bowl. Both teams were undefeated in previous Super Bowls, and you can imagine the kind of insane hype that matchup would have generated.
But it didn't happen...
The Chargers beat the Steelers in the AFC championship. So instead of a game for the ages, the historic season ended up being capped off by an embarrassing blowout and thoughts of what could have been.
No way I believe a rigged NFL would have passed up that opportunity.