It's true that in the overall player evaluation process for the NFL draft, a 40-yard dash time is just one number. But to NFL GMs, it's absolutely an important one, and the tenth of a second that Manti Te'o shaved off his 40 time during his pro day in South Bend on Tuesday could be the difference between a first-round and a third-round grade on some boards.
Every number, every measurement at the combine and at pro days becomes part of a player's profile, which NFL teams compare to players across the league. When you take all of those metrics into consideration, you can start to see what a successful NFL player traditionally looks like at every position. In Te'o's case, his 40 time at the combine (4.82 seconds) would have slotted him outside the spectrum for successful interior linebackers. As such, the odds would have been against him having difference-making success at the pro level, and teams may have been understandably hesitant to select him with an early pick.
But following his unofficial mark of 4.71 on Tuesday, he's right back in the first-round mix.