If you look at Braun's stats, his ISO is down but the real 'problem' is that he is hitting too many ground balls. His LD% is at career norms (18.4% this season, 18.3% for his career, 18.4% in his last MVP-caliber season (2012)), as is his HR/FB% (19.8% this season (not counting tonight's HR), 18.2% for his career, 18.8% in his 2011 MVP season). So he is still hitting the ball as hard as ever. However, over the last three season he is hitting a lot more ground balls and fewer fly balls. Combined with the fact that he's not as fast as he used to be, all those ground balls are really killing his AVG/SLG. I'm not sure what's causing him to hit the ball on the ground more, whether it is age or the thumb issue messing with his swing, but I'm pretty sure it's not PEDs.