The average 40 yard dash speed for an CB in the NFL is 4.25 to 4.45
4.8
inside linebackers speeds. fast is high 4.5 average is 4.6-4.7 slow is 4.8- low 5's pro speed is 4.49 low 4.59 average high 4.72
Because they dash for 40 yards.
4.6 - 4.7