“I used to wonder if I was crazy, because occasionally a seat would seem too snug,” says Karen Epstein, a volunteer usher at the Michigan Theater. “And I’d think, ‘That’s weird! I was just here last night!'”

Turns out that because of the curvature of the rows and the angled aisles, Michigan Theater seats come in three slightly different sizes–otherwise, the aisles wouldn’t line up right. If you come early and look closely (or bring a tape measure), you can pick a seat size that fits your posterior.

Epstein, also a Michigan Theater member, explains how she came into possession of such an arcane bit of trivia: “I actually go to the membership meetings. It came up because they were talking about replacing some of the older seats.”

Executive director Russ Collins confirms that you’ll find differently sized seats not only at the Michigan but at all the local “classic theaters: the Michigan, the State, Hill. At the Michigan and the State the seats are alternating eighteen-, nineteen-, and twenty-inch widths.”

Collins points out that the newer screening room at the Michigan has all large, comfy twenty-inchers. They were salvaged from what is now Urban Outfitters, and used to be the first floor of the original State Theater. “And if you look at the aisles” in the screening room, he adds, “the edges of the rows don’t line up.”