From GBPG:
Hayward's 40-yard dash time at the NFL scouting combine ranged from 4.53 seconds (the average hand-held time of his two 40s) to 4.57 seconds (his fastest electronic time), both of which are a little below average for his position. For instance, according to data from 1999 through 2014 compiled by Tony Villioti of the National Football Post, the average time for a cornerback at the combine is 4.48 seconds, based primarily on players' fastest electronic timing.