MSN posted its running back power rankings heading into Week 4, and I'll admit I went straight for the names I knew I'd argue with. Any list of the top backs in football this time of year is less a document than an invitation. Who's too high, who's too low, which guy did they forget entirely. I love that about them.

What I like about running back rankings in particular is that the argument doesn't need a spreadsheet to get going. A receiver can hide in a scheme. A quarterback can pad numbers in garbage time. A running back either moves the pile or he doesn't, and everybody in the stadium knows which one it was. When I watch Saquon Barkley get into the open field, all legs and menace, I think of Eric Dickerson's stride. That comparison is mine, not the list's, and you're welcome to fight me on it.

And the position keeps producing these generational arguments. Derrick Henry has spent years defying math that said a big back can't last, the same math Jim Brown ignored a lifetime ago, and whether he's first or fifth or tenth on any given list, the debate about him is the same one we've been having forever. Jahmyr Gibbs, to my eye, plays at a tempo that reminds me of a young Marshall Faulk, catch the ball in space and the whole defense is doing math it can't finish in time. Bijan Robinson belongs in that conversation too, and by every account he's earned his seat at the head of the table this young season.

My one quibble with any ranking this early: three weeks is a mood, not a season. I've seen backs look like MVPs through September and vanish by Thanksgiving, like they hit a wall only they could see coming. Let somebody get to 200 carries before we carve anything in stone.

Still, give me this argument over most. Debating running backs is debating football at its most fundamental, who's tough, who's fast, who's got the vision. The answers change. The questions never do. Check the list, circle your guy, and I'll see you back here in December when the picture looks nothing like it does today.