His numbers, then, paired with his medical history, sketch the narrative of his decline: Knee and foot injuries made it hard for Pujols to extend and slam the ball the other way. He's no longer crushing outside pitches as he once did; against offerings low and away, Pujols has just seven extra bases in 107 at-bats this season. And given that his O-swing percentage shows that Pujols no longer passes on those iffy pitches, something else peers out from the slugger's advanced metrics: The man seems anxiety-ridden at the plate these days. His power is down, so he's chasing pitches he shouldn't, and now his stat lines are closer to those of George Bell or Lee May than Mel Ott or Jimmie Foxx.
The first wave of sabermetrics was built on numbers that had been public for years; the statheads developed tools useful for evaluating seasons by players and teams. Now that pitch-by-pitch data is available, we can discern why Pujols' decline has taken its particular shape. Statheads and fans alike have long enjoyed acting as GMs. Next up, we get to play batting coach, if not therapist. Let's play ball!