Well, Belichick's MO when he gets a pick that high is to take the rare specimens, the tiny percentage of guys that don't come around often, usually the big and fast defensive linemen. What George Young used to call the Planet Theory guys. The 310 pound run stuffers that are also great athletes. The 250 pound 6'8" tight ends with soft hands that run like antelopes and can't be covered by linebackers or safeties, but will steamroll you in the running game. The mammoth left tackle with nimble feet and a nasty demeanor that excells at run and pass blocking.
Unfortunately, none of those guys are here, unless he thinks Mario Williams can play 3-4 DE. So he'd probably attempt to trade down to draft Hawk or Vernon Davis. Forced to choose at #1, I'd say he'd probably tab Hawk.
I don't want to delve again into the Reggie Bush is overrated spoken word festival, but Desmond Howard is an apt comparison. Sure, now you say Bush was better, but at the time Desmond was going to be the next Jerry Rice. Raghib Ismael is another good comparison, of a guy that was quicker and faster than 95% of the NCAA, but was suddenly lined up against people as athletic as he was. Reggie Bush will be an excellent third down back and returner. He'll be an asset to the Texans. He isn't worthy of the #1 pick. Probably around #15 or so. The Hall of Fame talk is humerous. If Bush played 25 years ago, yes, he might be the next Gale Sayers. In today's game, Gale Sayers wouldn't be Gale Sayers. The guys I would most compare Bush to in the recent past would be Brian Mitchell and David Palmer.
