On the 4th and inches play, it's worth watching Michael Oher's contribution (or lack thereof). "1 Winning Drive" highlights that play in the replay package this week. Just looking at how it was blocked, it makes me think that the point of the shift might have been to set up the run as a cut-back to the left behind the "jumbos". The right side gets pushed back a hair but seems to put helmets on helmets. The left side did a decent job getting some push. Except for Oher. He actually flinched before everyone else (maybe early), you can see it clearly on the show. Then he just gets smoked off the snap by his guy, who proceeds to then make the tackle. He needed to get over to seal Liuget off, and didn't even come close. He flinched at the worst possible time, then got caught "stopping himself" when the actual snap was made. That left him flat footed, while Liuget was virtually untouched.
If Oher just battles him to a draw, there was plenty of space for Pierce to cut back and pick up the first down... and probably several more yards. But Oher did virtually nothing on the play. In all honesty, the play would have looked exactly the same if Oher hadn't even been on the field and they ran it with 10 men.
