May 5, 2014
The Winding Path of Albert Pujols, Via PITCHf/x
In the beginning (of the millennium), there was Albert Pujols, and Albert Pujols was good. Bursting onto the scene in 2001, Prince Albert immediately won a Rookie of the Year award and posted a 7 WARP season. What followed was perhaps the best 10-season stretch since the glory days of Mickey Mantle. Each year for those 10 years, Pujols recorded an MVP-level ~6-10 WARP season, replete with 30-40 homers and an OPS above 1.000 (even sprinkling in a couple of Gold Gloves for good measure).
Then there was the fall from grace. As it turns out, even the Machine ages. Beginning from his peak season in 2009, his WARP fell precipitously: 12.8, 10.4, then a humble 6.3, on to 4.0, and last year a barely average 2.2 WARP. Contract dynamics aside, the legend of Albert Pujols seemed to have disappeared in a historically unprecedented way.
A couple of weeks ago, I wrote about how one could reverse the usual direction of PITCHf/x analysis, using it to study not pitchers but batters. By examining trends in how certain hitters were pitched to, I reasoned, we could infer something about the scouting report of each player. For example, I saw that pitchers tended to adjust their fastball frequency depending in particular upon the age and slugging ability of the opposing hitter.
I turn that same approach now on Albert Pujols. In the PITCHf/x era, Albert Pujols has been everything from MVP to average. He’s been injured, he’s been ineffective, and he’s also posted the highest BWARP season of all time. If ever there was an ideal case for understanding how pitchers adjust their approach to a hitter as that hitters’ skills change, it is Albert Pujols.
What follows, then, is a brief history of Albert Pujols from the perspective of PITCHf/x. I’ll start with the 2009 season, Pujols’ best, and continue through to the present, at which time Pujols appears to be making a sort of comeback. The PITCHf/x history of Prince Albert is a story of constant adjustment, in which Pujols struggled to catch up to the tactics with which pitchers attacked him.
The Glory Days
Pitchers approached him accordingly. I showed before that the most powerful hitters tend to receive the lowest fastball frequencies. In 2009, Pujols was seeing fastballs 55.6 percent of the time, the 10th-lowest rate in the league, near names like Matt Kemp and Raul Ibanez (back when they were good).
Another way to look at how a batter is approached is via location. While the reasons for varying fastball frequency are a little opaque, it’s entirely obvious why a pitcher would choose to pitch away from a good hitter’s strike zone. In the strike zone, a pitch can be hammered for a hit, whereas outside of the zone—or further towards its edges—the contact is likely to result in a weakly struck ball, easily played for an out. The flip side of the strategy is that a good hitter will allow the pitcher to chew away outside the zone, knowing that a walk is plenty valuable.
In this way, the median distance from the center of the zone at which a given hitter is challenged can be seen as an indication of how feared that hitter is. I’ll call this measure the “zone distance.” The bigger the distance, the less a pitcher is willing to challenge a hitter in the zone. By this metric, Pujols was among the most dreaded sluggers in the league in 2009.
The players above him on that list tended to have poor plate discipline and were eager to swing at outside pitches (Sandoval being the best example). Pujols did not have poor plate discipline, amassing more than 100 walks that year; pitchers simply feared him.
That didn’t last. By the 2010 season, Pujols was already being treated very differently. His average zone distance had fallen to 31st in MLB (among batters who’d received more than 1500 pitches), and he was seeing pitches on average about a half inch closer to the center of the zone. Curiously, his fastball frequency didn’t much change (still 55 percent). In 2010, Pujols put up a very respectable WARP and TAv, about equal in value to his 2008 season.
Even though things looked to have been going swimmingly from 2009-2010, there were dark clouds gathering. Look at this smoothed graph of Pujols’ median zone distance.
The red line is the smoothed estimate of the trend, and the blue vertical line indicates the end of the 2009 season. Note that it is decreasing in a small but noticeable way within both seasons, perhaps portending future disaster. Even in two of Pujols’ most magnificent years, pitchers were beginning to test how close to the center of the zone they could throw.
The first time Pujols’ results began to match that troubling tendency was in 2011. That year, as in the year before, his power and on-base skills simultaneously took a plunge, resulting in a then-career-worst .318 TAv. At the same time, his fastball frequency abruptly jumped to 59 percent. His median zone distance fell again to 1.05 feet, continuing the above decrease. These numbers put him in an echelon of hitters in which he seemingly did not belong, close to guys like Nick Swisher and John Buck.
Sadly, the expectations were not met. Continuing the trends that began even when Pujols was in St. Louis, pitchers aggressively pounded the zone with fastballs at a zone distance of ~1.05 feet. Surprisingly, Pujols was helpless to punish those in-zone fastballs. His swinging strike percent continued its upward march, from 5.7 percent (2010) to 5.9 percent (2011) to 6.3 percent (2012). His TAv plummeted to a more pedestrian .302. Still, he finished the season with a respectable (for anyone not named “Albert Pujols”) 4 WARP.
At no point in the journey of Albert Pujols did pitchers really vary the mix of locations at which Pujols was attacked. Some rudimentary cluster analysis shows that Pujols generally received pitches at the four corners of the strike zone, with the two outside corners getting more pitches than the inside. That distribution of pitches was approximately constant throughout Pujols recent run. Instead, what varied was how close to the zone pitchers dared to place the clusters. Take a look at this graphic, which shows the median position of an Albert Pujols pitch throughout the seasons I looked at.
The blue lines indicate the horizontal and vertical centers of Pujols’ strike zone, and the green text indicates the median location of a pitch in that respective year. The median pitches are always down and away, although they seems to move a little more inside as the seasons progress. The strategy, then, wasn’t so much to confuse Pujols with a lot of different locations as it was to continually dare Pujols with increasingly hittable pitches.
The story in the following year, 2013, was one of injury. Pujols was diagnosed with plantar fasciitis, and this caused him to miss about a third of the season. Even when he was playing, however, he put up a career-worst (by nearly 20 points) .285 TAv.
The end result of 2012-2013 was a seeming leviathan of a contract, weighed down by a player who struggled last year to be even average. At this stage in his career, Pujols looked all but cooked. Injuries beget injuries, which cut playing time and reduce effectiveness even when a player is in the lineup. And as if that wasn’t enough, I’ve shown that the signs of Prince Albert’s decline were present long before he landed on the DL, suggesting an underlying decay in his skills which opposing pitchers had noticed and were exploiting. In an epic, decades-spanning career that will one day land him in the Hall of Fame, the end of the 2013 season looked like Albert Pujols’ All Is Lost moment.
The Return (?)
This is the same kind of graph as before, charting the trend in distance from the center of the zone. The first, white part of the graph is Pujols’ zone distance for 2013, and the blue shaded area represents the same thing for 2014 so far. Oddly, Pujols’ zone distance started high in 2013 before decreasing to his new normal level of ~1.05. This year, his zone distance is even lower (1.04) and declining still. His fastball frequency is increasing as well, and now sits at 61 percent.
Nevertheless, the results have been surprisingly good so far, which Pujols attributes to improved health. But has Albert also adjusted his approach in some way?
Perhaps, but as of yet, we may lack the sample size to discover how. One intriguing sign can be found in the pitches at which Pujols swings. I calculated the median zone distance for only the pitches at which Pujols took a cut. For 2011, he swung at pitches .826 feet from the center of the zone; for 2012, that went up to .85 feet. Recall that in that time he was seeing pitches which were usually closer to the center of the zone. Getting a lot of in-zone pitches but then swinging at far-away junk is a sure recipe for poor performance. This year and last, he’s cut the distance of his swinging pitches to .8 feet, which is on par with some more patient hitters (David Ortiz, for example). This change in Pujols’ behavior qualifies as a good sign, but whether he can maintain it—and whether pitchers adjust correspondingly—remains to be seen.
Regardless of the reasons, his slugging has certainly improved. Given the drama with which Pujols’ contract has unfolded, the Angels will take any production the Machine can offer, even if it comes in bits and spurts.
It’s interesting that some changes to Pujols’ pitch profile pre-date the changes in his performance. This pattern could be a result of advance scouting that leverages information to which we are not privy. For instance, opposing teams may have seen the signs of Pujols’ age and injuries catching up to him before his performance flatlined from 2012–13.
Along these same lines, as noted above, the indicators of Pujols’ intimidating stature have at best stayed constant and maybe continued downwards, with the interesting exception of his swing distance. Whether Pujols’ resurgence will continue or reverse itself is still unsettled. But in view of the whole of Prince Albert’s career, I wouldn’t count him out yet. As La Russa observed, Pujols seems to be able to do anything—including, perhaps, coming back from an unprecedented mid-career crater.