In June of 2006, Albert Pujols strained a muscle on his right side and suffered his way through the worst month of his career. Despite the nagging injury, Pujols managed to finish the season atop the NL with a .448 wOBA, and the Cardinals went on to win the World Series.
From 2007-2010, Pujols paced the league in slugging percentage and wOBA by a large enough margin to remove any doubt regarding his best-hitter-on-the-planet status. He has a skill set that basically leaves him immune to slumps.
A legendary slugger who walks more than he strikes out, Pujols has established himself as a model of elite consistency.
Because of this, it seems odd to write a piece about Pujols struggling in the middle of May. It's even stranger to consider that, despite his problems, his team is leading the major leagues in runs scored.
In June of '06, the Cardinals limped to a 9-16 record as Pujols battled injury. This year, the team has been carried by outfielders Lance Berkman, Matt Holliday and Colby Rasmus. Berkman and Holliday rank first and second, respectively, among National Leaguers in wOBA. Rasmus is currently hitting .299/.390/.461 and St. Louis sits atop the NL Central at 21-15.
So where is Pujols?
It's still early enough in the season that all analysis should be taken with small sample size in mind. That said, we're looking at the worst 36-game stretch of Pujols' career. He's currently hitting .268/.338/.442. For the first time since his rookie season in 2001, Pujols is posting a higher strikeout rate than walk rate. His ISO (Isolated Power) is under .200, and he's sporting a sub-.400 wOBA.
It's tough to find out where Pujols' current problems are rooted. Nothing in his basic stat line sticks out as an indicator of why he may be struggling, but there are a couple of factors that could help us figure things out.
First, he isn't swinging the bat as often as he usually does. His total swing percentage is down two percent from his career marks, but the more telling number is how he's handling pitches thrown in the strike zone.
Pujols has a lifetime swing rate of 65.2 percent at balls in the zone. This year, that number is down to 60.9 percent. However, his contact rates are still in line with his career marks. That number brings us to the only statistic that really jumped off the page.
Pujols has one of the best, most controlled swings in the game. Very rarely does he find himself off balance, chasing balls outside of the strike zone. For his career, when he swings at pitches thrown outside of the zone, he only makes contact 67.5 percent of the time.
He's used his keen batter's eye and mastery of the strike zone to sustain very low O-Swing percentage (percentage of pitches outside the zone that generate a swing) numbers.
For the most part, Pujols is very selective, and thus makes most of his contact with pitches he can square up on in the zone.
However, Pujols is currently making contact on 87 percent of swings at pitches outside of the strike zone—87 percent! That's 20 percentage points higher than his career average. He's only been over 70 percent three times in his career.
His .252 BABIP is a career low. More often than not, when a player's batting average is anomalously high or low, BABIP is the culprit. His .252 isn't a terrible number, but it does tell us that Pujols has had slightly less success on batted balls than he's had in the past.
This is due in part to luck, but he has a history of posting excellent numbers in spite of good or bad fortune. When you're consistently hitting the ball hard enough, it's easy to overcome the few line drives that rocket themselves right into an outfielder's glove. Sure enough, he's on pace to hit a career-low 76 line drives this season.
Pujols just isn't making good, hard contact with the same consistency as he has throughout his career. I believe this has a lot to do with his increased contact rates on balls outside the strike zone.
At this point in his career, we have to give Pujols the benefit of the doubt. He's established himself as the best hitter, by a large margin, in the game over the past decade. We're not even a quarter of the way through the season, so we should still assume that he'll find his stroke and start mashing again.
Still, Dan Szymborski's ZiPS has Pujols quickly returning to form but failing to post a wOBA above .400 for the first time in his career. Fortunately for the Cardinals, Matt Holliday and Lance Berkman have combined to do their best Pujols impersonation while their best hitter figures things out.
However, those guys will soon regress to their mean. As that happens, the Cards will hope Pujols begins progressing to his. I think he will, but this has nevertheless been an interesting 36 games for baseball's best player.