Although the all important "game tape" is the true measure of a player, the NFL combine, strips players down to t-shirts and shorts and asks them to perform various agility,strength and speed drills.
Throughout the combine most teams will use this evaluation session to confirm their initial player grades. There are some players , however that can improve their draft stock by turning in a great 40 time. I have highlighted 5 players that fall into that category. In most cases, a great 40 time doesn't automatically increase a players draft grade but it can cause NFL teams to take another look at the tape.