Goff is not a runner. He had nifty feet so he can sidestep rushers to buy time. On that Int sack he looked middle and left and was hit from behind by an unblocked blitzed as he was throwing. That can't be on him at all. First, somebody, usually the RB, has to pick up the blitzer. If the first target was open the ball would've been out way before he got smashed. So, blame the scheme, or the blown blocking assignment or the receiver who couldn't find an opening. Not looking to blindly give Goff a free pass, but that wasn't on him in any way or an indication of any last of ability. If you are any QB including King Brady and you get blasted in the back on a "watch out" play, bad things are gonna happen.
