Sports fans may have more in common with political partisans than you might think — specifically, a home-team bias that shapes what they believe to be true about the world.

As a result, the beliefs of fans — or partisans — who know the most about a particular controversy are often more polarized, not less. It’s true in politics, science and, perhaps surprisingly, sports.

That’s what my colleagues and I found when we examined what the public believes about the ball-deflation controversy that started in last season’s N.F.L. playoffs and that is likely to continue to provoke further debate this week before Sunday night’s game between the New England Patriots and the Indianapolis Colts. (For those who didn’t follow the affair: Two Patriots employees were accused of conspiring to release air from a set of game balls in last year’s A.F.C. title game victory against the Colts. An N.F.L. inquiry backed up the accusation, and the league suspended Patriots quarterback Tom Brady for four games for what it believed to be his role in the plan. A federal judge later vacated the ban. There’s more to the story, but that’s enough to get you through this article.)