In my draft board, and in Dawghouse Blog's draft board, we advocated drafting Calvin Johnson (if he's still there) and then trading him.
While it sounds nice and easy, it has some pratfalls. Which would explain why its not a standard practice.
Every year, teams "threaten" to take players who are not their number one choices so that they can induce a trade with a lower team, and it rarely works. Which makes sense: If the team one spot ahead of you is threatening to take your player, you can call their bluff. If they really do take that player, there is no reason that you can't work out the trade while you are on the clock (ala Chargers/Giants swap of Eli Manning for Phillip Rivers).*
So the next logical step for the team that wants to trade down is to draft that player to force the lower team to do the trade. But there are a couple things that can now happen:
>> The lower team DOESN'T really want that player, at any price. You would only get into this situation if the lower team was doing an incredible bluffing job. I don't believe that Tampa or Washington would really pass on Calvin Johnson no matter what.
>> The lower team DOES want the player, but is only willing to pay below-market price. This is a likely scenario. But it still doesn't seem to be that much of an issue. So we take Johnson and can only get a 5th rounder out of Tampa. I could live with that.
>> The lower team DOES want the player, and will pay through the nose for him. That is the ideal scenario.
So, it is a bit of Russian Roulette, but the downside risks seem to be pretty minimal. Worst comes to worst, you still end up with a great player, just the wrong great player.
*Unfortunately, no one ever explained this manuever to Butch Davis, who gave Detroit a 2nd round pick so that we could take Kellen Winslow Jr.
Clark Judge on CBS Sportsline has an article saying why the Browns "have" to take Peterson. But he fails to rebut one of the most important knocks against Peterson: his explosiveness and dynamicism means nothing when he's on the bench:
>> His injury history is troubling. Both the number of injuries and the types of injuries. Sure, they may all be "fluke" injuries, but so were most of Courtney Brown's injuries. It doesn't mean anything in the end. Some guys are just injury prone.
>> Even if he stays healthy, he's still only going to be helping us on first and second downs.
>> Time after time teams have proven that you can win with a less than stellar back, or with a tandem of backs. Quarterback by committee, NO! Running Back by committe, SI!
Peterson sounds exciting, and I wouldn't mind being proven wrong if we take him and he stays healthy and productive. But I'm not going to hold back from saying "I told you so" when he gets hurt.
Dawg Pound South has a great post making the argument for drafting an offensive tackle.
Since he layed out alot of the numbers, I would like to add to that my own qualitative opinion:
The roles of quarterback, running back, and wide receiver can change drastically from scheme to scheme within the NFL, and espescially from college to the NFL:
>> Running backs need to follow more defined blocking patterns, since they can no longer rely on outrunning and overpowering NFL caliber linebackers and safeties. They also need to be able to pick up more complicated blizting schemes.
>> Quarterbacks have to contend with more frequent blitzing, and also have guys checking their reads to pick off passes to their primary targets
>> Wide Receivers have bigger, more physical CBs who keep them from running their routes and showing off their speed
Obviously tackles have new schemes to contend with and bigger, faster blitzers to worry about. But their job doesn't change neary as much: Keep your quarterback safe, and knock opposing defenders away from the run.
I think thats why its easier for personel guys to project college linemen than other positions. It makes the tackle a much safer pick. You may be losing the "upside" of getting a game-changing skill player, but you eliminate alot of the downside too.