The Steelers made RG3 beat them with his arm in Week 8.
Robert Griffin III has been sensational in the first eight games of his rookie season, but he'll be the first to tell you he is not perfect and there is plenty of room for improvement.
That flaw is the elimination of one facet of his duel-threat nature. Pittsburgh limited him to just eight rushing yards on six carries, putting the game completely on his arm.
Griffin completed only 16-of-34 passes for 177 yards and a touchdown. By taking away his running ability, the Steelers made RG3 try to beat them with his arm, something he could not do.
This may be a flaw in the rookie's game, as teams may try to make the rookie beat them by bottling him up on the ground. In Week 5, the Atlanta Falcons were the only other team that limited his running ability (one carry, seven yards) before knocking him out with a concussion.
Griffin has no doubt made great throws in his rookie tenure, but the stats seem to suggest that the more times he throws, the less effective and accurate he becomes.
The Redskins are best-served when he and Alfred Morris lead a strong ground attack, making it more comfortable for him to make smart throws and avoid turnovers.
RG3 has burst onto the scene as a one-of-a-kind quarterback who can throw the ball 60 yards down the field with accuracy and also run incredibly fast while being elusive. He works best when he can do both of those things, so the Steelers keyed in on eliminating the run game.
Another flaw that is apparent in RG3's game is that while he is a great runner, he has to know when to go down and avoid taking the big hit like he took in Week 5 against Atlanta.
His frame is stronger than a Michael Vick, who has taken his fair share of hits, but one hit could give him a second concussion and/or knock him out for the remainder of the season.
Griffin plays with no fear, but he must be wary in avoiding potentially dangerous hits.
Finally, the sensational rookie must find ways to win. This may seem overly critical for a man who is doing everything for a team with marginal talent on offense and injury problems on defense, but it comes with playing the position.
His play on the field must be inspiring his teammates to step their games up and come along for the ride.
Fellow rookie QB Andrew Luck has the Indianapolis Colts at 4-3 with a similar if not less talented roster than the Redskins.
RG3 has been nothing short of phenomenal in his rookie campaign. If he can shore up these minor flaws, he will be a force in this league for years to come.