Top 5 inside D-tackle prospects

Louis Nix III is an imposing force inside for the Notre Dame Fighting Irish. Jonathan Daniel/Getty Images

Debating the playing weight for defensive tackles is sort of like debating the horsepower in a car. What the manual claims doesn't really matter as much as performance. The number is almost secondary.

At 350, can it maneuver like a smaller car?

At 300, can it still drive through a brick wall?

Louis Nix III has always been a big guy who could move like a smaller one. As a high school recruit, his evaluation noted that he (even at a listed 318 pounds), "Displays solid speed for a big guy and adequate short-area, change-of-direction skills." And brick walls? Sure. It's hard to ever trust an "official" weight until it's the one we get from the NFL combine, but I've heard Nix is going to play at more than 340 pounds this fall, which certainly will have us keeping a close eye on his burst off the snap and his ability to shed blocks.

But from all indications -- and certainly by his brief time at QB -- he still looks like a big guy who can really move. He starts the summer as my top-rated defensive tackle for the 2014 NFL draft class.