Run blocking is a lot harder than pass blocking. You have to be quick and explosive. you have to have excellent timing to coordinate your block with not only the person beside you, but all of the blockers and the back. It isn't just all shoving someone around.
Think of track athletes. While they are all in fine shape and great athletes, you can't expect to turn a sprinter into a distance runner, and vice versa. You can't expect a sprinter, just because he is fast, to be a good hurdler. Run blocking takes great footwork, more quickness and a better reaction time than pass blocking. It takes practice and technique to be able to leverage and turn a tackler out of the way. It also takes a certain nasty streak. Much of pass blocking is defensive, getting in the way of rushers and absorbing punishment. The best offensive linemen are comparable to decathletes, who may not be the best at all techniques, but are very good at all of them.
I'm not saying that these guys can't do it, but you can't expect them to learn the timing and techniques needed in one spring and one fall.
Think of track athletes. While they are all in fine shape and great athletes, you can't expect to turn a sprinter into a distance runner, and vice versa. You can't expect a sprinter, just because he is fast, to be a good hurdler. Run blocking takes great footwork, more quickness and a better reaction time than pass blocking. It takes practice and technique to be able to leverage and turn a tackler out of the way. It also takes a certain nasty streak. Much of pass blocking is defensive, getting in the way of rushers and absorbing punishment. The best offensive linemen are comparable to decathletes, who may not be the best at all techniques, but are very good at all of them.
I'm not saying that these guys can't do it, but you can't expect them to learn the timing and techniques needed in one spring and one fall.
