Speed is the rate at which an object's position changes, measured in meters per second. The equation for speed is simple: distance divided by time. You take the distance traveled (for example 3 meters), and divide it by the time (three seconds) to get the speed (one meter per second).
Of the three players discussed above who covered the 40 yards and also the 20 yards shuttle in the least amount of time?
Line up McCaffrey against your lover Duggan and 9 out of 10 times McCaffery not only beats him on a sprint, but smokes him. He runs past defenders at a rate not seen by Duggan.