People always say certain college qb's can't function in a "pro-style" offense. I understand this, but why dont any pro teams run "college style" offense? if a qb has played that all his life, why change it, especially if it can be really effective?

It's all about speed.

For example: When you run an option offense, you are running to the outside 70% of the time. A fairly quick QB and an above average back have the speed to get to the outside in college and pick up some yards. But when you get to the pros, you'd need a serious speed back and an equally fast QB to have any chance of making that happen. Since there are only a handful of backs that are even close to fast enough, and almost zero QBs with that kind of speed, it's hard to run that offense with any effectiveness. And once you're tagged as an option team, all your opponents have to do is assign their fastest DBs to the QB and RB, and you're toast on every option play.

Run and shoot offenses are way too pass heavy. They throw a ton of screen passes, which will be 2 yard gains in the NFL because the DBs can get to the WRs so much quicker. Run and shoot offenses will only work in the NFL if your running back can pick up 7 yards on a draw play 4 or 5 times a drive, and that's not happening.

Because college style offenses have too much running which isn't very effective in the NFL because the average NFL player is a lot bigger than the average college player

Because the NFL is governed by conventional wisdom when it comes to offense and defense. College QB's are more likely to run the ball more and often run the option. The option, wishbone, wing-t, single wing, etc, are all found in high school and college, but never in pro football. Some college quarterbacks also are known to operate well when on the move, outside the pocket. The pro game generally calls for a disciplined QB who can hang tough in the pocket, and step up and make a throw, something which alot of college QBs seem tempermentally unsuited for.

Because the college style offense such as the "Run and Shoot" is designated to accomodate a slower and more complex player. The proffesional style offense is more equipped for the faster bigger type player that play in the NFL

There was a "college style" offense. It was done by Steve Spurrier. To an extent, the dumbed-down offense that Mike Vick ran was a college offense. The reason a college offense does not work is because of the speed in the NFL.

Everyone in the NFL can be fast. Not Reggie Bush fast, but still fast. In college, most programs that are smaller are depleted in the talent and the speed that can be pushed through, so a faster offense runs all over them.

I will let other explain the why they do and don't. But there are some college teams who use a pro--set offense. Its done mostly in the PAC10, although is more of a hybrid pro style.

to make things easier on my explanation if your qb has talent he can play in any type of offense no matter what. i'll give examples: Vince Young and Donovan McNabb.

but most qb's are brought up to be that conventional pocket passer. examples: the Manning bros.

most NFL teams now are turning to qb's who can run and pass. but pass first and run second. not look at first option and then run if hes covered.

i'll give you two examples of college style qb's who wont or didnt make it in the NFL but had very good college carrers. Troy Smith and Eric Crouch. played in college style offenses and won national championships but as NFL qb's they wont be good.