I have posted this before, but people lose their mind about statistics that don't matter during the combine.
There is remarkably little correlation between short shuttle speed and nfl success for wide wr's. If there was, you would see the players with top times have good nfl success. That is not the case
2011 top 5 Austin Pettis 3.88, Jeffery Maehl 3.94, Dane Sanzenbacher 3.97, Terrence Toliver 4.03 and Cecil Shorts 4.07.
2010 Top 5 Blair White, Scott Long, Emmanuel Sannders, Stephen Roberts and Andre Roberts.
2009 Kevin Ogletree, Kenny McKinley, Tiquan Underwood, Brian Hartline, Johnny Knox.
2008 Arman Shields 3.96, Andre Caldwell,Harry Douglas, Ryan Grice- Mullen, Jaymar Johnson 4.18
2007 Mike Mason, Anthony Gonzallez, Paul Thompson, Chris Davis Chansi Stuckey.
Meanwhile, some very successful NFL wr's have had poor scores:
AJ Green (19th rank) 4.21, Julio Jones (25th rank) 4.25, Stevie Johnson (13) 4.26, Jordy Nelson (26th rank) 4.35, Sidney Rice (30th) 4.34, Marques Colston (32nd rank) 4.44.
There simply is not cut-off number like there is 40 times (4.7+ is almost always a deal breaker for a wr).