On Saturday, Wisconsin's Melvin Gordon set a new Football Bowl Subdivision (FBS) record for most rushing yards in a single game, with 408 running yards against Nebraska. Gordon's performance should be immediately inducted into the pantheon of great college football accomplishments, but what I'd like to discuss here is that a wide array of factors should be taken into account when deciding which FBS running back had the best-ever single-game performance.
In addition to accumulating rushing yards, I think running for touchdowns can help a running back put together a day that's worth debating as the greatest ever. For example, on November 17, 2012, Temple's Montel Harris rushed for 351 yards on 36 carries against Army, including seven touchdowns. While Gordon had more yards than Harris on fewer carries, he still would have scored fewer than seven touchdowns if he'd played the entire game (based on the pace at which he scored touchdowns through the first three quarters of the game).
Other types of yards can also help running backs put up single-game performances worth considering as the greatest ever. On November 4, 2000, Utah State running back Emmett White racked up a whopping 578 all-purpose yards in a game against New Mexico State. Well over 100 of those yards were on receptions. I think a good way to evaluate White's day would be to determine how many of his receiving yards came with him lined up in the backfield, because it would help reflect his performance as a running back.
There are potentially endless variables one could come up with when discussing which college running back had the best single-game performance ever. Who had the best blocking? Which player's opponent had the best rush defense? What was the weather like for each player? The list goes on and on. So while a game such as the one Melvin Gordon played on Saturday is certainly great, don't make anybody's day the day until you've examined all the factors that make it so fantastic. There are, after all, quite a few of them.
**Note: All statistics used in this post came from sports-reference.com/cfb, except for the facts about Melvin Gordon breaking the single-game FBS record for most rushing yards and his playing only three quarters of Saturday's game. I used a combination of this ESPN.com page and this Deadspin.com article for those facts, and the facts also seem to be available in a variety of other sources.