re: What happened to JJ in 2010?

Jefferson's biggest issue was pocket presence and understanding how a pocket works. In 2010, his main issue was he faded back in pockets too far causing sacks (37, in fact). His other issue is instead of running through run lanes, he would loop outside of his tackle, allowing the defensive end to easily come off the block and sack him. You'll notice that his best games were those where he ran straight up the middle to escape pressure. There is a reason for that.