In 2011, his first season with the St. Louis Cardinals, Matt Carpenter played exclusively at third base and recorded half of his starts batting in the eighth position. Granted, this is a roundabout way of saying he started four games and he batted ahead of the pitcher in two of them (he also batted 2nd once and 7th once).
Not much of substance can be derived from Carpenter's nine-day stint in the big leagues in June 2011. After all, he wore #19. This was proto-Carp, at best. His rookie season of 2012 provided something approaching a reasonable sample for seemingly gaining insight into what Carpenter's roles would be. He played primarily at the corner infield positions and although he started at every spot in the lineup aside from first (really), third, and ninth, he primarily batted second or seventh.
In 2013, his roles changed dramatically. Following the departure of Skip Schumaker and lacking a desire to move forward with Daniel Descalso as the everyday second baseman, Carpenter made the at-the-time radical position move to second base. It worked out beautifully, as he played the majority of his games there, fielding competently and also allowing the Cardinals to utilize his increasingly potent bat on a daily basis.
And on April 18, Mike Matheny made one of his more saber-friendly managerial decisions, placing the high-OBP and relatively flat-footed Carpenter in the leadoff spot over the faster, less walk-inclined Jon Jay. And Carpenter had a breakout season primarily as a leadoff-hitting second baseman.
In 2014, following the departure of David Freese, Carpenter moved back to third base, though he continued to hit primarily as a leadoff hitter. He continued to lack prototypical speed, but he fit the new-age leadoff prototype even more closely: while his vaunted 2013 doubles power declined, his walk rate increased. Seemingly, even while lacking speed and playing a position not typically associated with the leadoff spot, Carpenter had cemented his position in the lineup.
And then 2015 happened, where Carpenter's plate approach changed. He still walked a lot, but after hitting 6, 11, and 8 home runs in his first three full MLB seasons, he belted 28 in 2015. His spot in the batting order fluctuated, though this was largely the result of numerous injuries. But regardless, a new concern developed with Matt Carpenter; it wasn't that he wasn't capable of batting leadoff, but rather that he could cause more damage for the Cardinals offense batting elsewhere in the lineup.
So far in 2016, Matt Carpenter's usage has been somewhat predictable. 42 of his 44 starts have been at third base, and 42 of his 44 starts have been from the leadoff spot. But as the result of upcoming roster moves, the former may be about to change, and depending on how averse Mike Matheny is to making unusual lineup moves, so might the latter.
The anticipated return of Jhonny Peralta, currently on a rehab assignment, leaves open questions about the potential ripple effects of adding the veteran back into the lineup. Two months ago, it seemed that Peralta would simply retake his spot and his replacement would acquiesce the position, but the emergence of Aledmys Diaz, who entering Tuesday's game had "regressed" to a 155 wRC+ with a .962 OPS, complicates the matter.
One theory floating around is to move Matt Carpenter from third base to first base. Intuitively it makes sense: in his three seasons as a full-time starter, he has been a below-average fielder, ranking in the 26th percentile among full-time second basemen in UZR/150 in 2013, the 38th percentile among third basemen in 2014, and the 25th percentile in 2015. At 30, Carpenter is unlikely to improve substantially in the field. And while Matt Adams has hit well in 2016, there are still many questions about his long-term future as an everyday first baseman, particularly when facing left-handed pitching.
On April 27, Matt Carpenter started at first base and batted leadoff. On the surface, this makes sense: the Cardinals were playing three fairly versatile infielders (Diaz, Ruben Tejada, Jedd Gyorko) and the arguments for Carpenter as an idealized leadoff hitter remain intact. Amazingly, though, this was the first time a Cardinal had started at first base batting first since 1993, when Bernard Gilkey, normally a left fielder, started two (of his three career total) such games.
Prior to Gilkey, a Cardinal had not done this since Matty Alou in 1972. In the 96 seasons since the end of the Dead Ball era, this has occurred only 47 times for the Cardinals by 10 different players, including Carpenter.
Historically, there is a logical reason that leadoff hitters have not typically been first basemen: leadoff hitters have generally been fast players, and fast players normally play defensive positions at which speed is more beneficial. However, in the modern era of high-OBP leadoff hitters, where speed is always welcome but hardly considered the top priority, it remains a rarity. Only 12 players this decade have started multiple games at first base batting leadoff, and over half of the games fitting this criteria have been among three players: John Jaso (who has become a mainstay in these spots for this year's Pittsburgh Pirates), Logan Morrison, and Wil Myers.
Somebody such as Joey Votto would make sense to bat first, but the honest truth is that a first baseman batting first just seems weird. This doesn't mean first baseman shouldn't bat first, mind you. But sometimes, it is difficult to ignore what we are accustomed to seeing. Even when playing second base, a position which produces a decent number of leadoff hitters, it was initially hard for many to accept a base-stealing non-factor such as Carpenter there.
Matt Carpenter is the most prolific leadoff hitter of the Mike Matheny era, and the four who trail Carpenter in leadoff starts are more traditional in the role: Rafael Furcal, Jon Jay, Kolten Wong, and Peter Bourjos ranged from quick to outright fast. It is impossible to know for sure if Matheny will continue to seemingly make an exception for Matt Carpenter as leadoff hitter even as he increasingly resembles Anthony Rizzo rather than a speedster.
For all of the criticisms Matheny has faced from sabermetric-leaning fans, he has handled Matt Carpenter very well. It would behoove him to continue to apply logic, that an ultra-productive on-base machine getting a lot of plate appearances is a good thing, to his lineup construction.