The Captain's Blog

(In addition to appearing at The Captain’s Blog, this post is also being syndicated at TheYankeeAnalysts.)

At this point in the season, Mark Teixeira is usually starting to emerge from his April doldrums. This year, however, the Yankees’ first baseman got off to a hot start. As a result, Teixeira’s current OPS+ of 141 ranks above his career rate and on par with some of his best seasons.

Although he has been one of the Yankees’ best offensive performers, one part of Teixeira’s game has been a little concerning. Despite establishing himself as a well-rounded hitter before joining the Yankees, Teixeira has gradually turned into a more one-dimensional slugger, particularly when batting from the left side.

As evidenced by the chart below, Teixeira has evolved from an all-field approach into a much more pull conscious batter. Although the percentage of balls hit to center and the opposite way have fluctuated during this period, the overall trend toward pulling the ball has persisted since 2007. Also evident from the chart is a potential relationship between the first baseman’s production and where he hits the ball. Over the years, it seems as if Teixeira’s output has increased in accordance with his use of all parts of the ballpark, particularly the opposite field.

Using All Fields: Where Mark Teixeira Hits the Ball (% of batted balls)

Note: Off field = Opposite + Center.
Source: fangraphs.com and baseball-reference.com (OPS+)

Although it’s clear that Teixeira has been pulling the ball more overall, has the same trend emerged from both sides of the plate? By isolating Teixeira’s directional splits based on handedness, we can better answer that question.

Mark Teixeira’s “Spray Chart” as LHB, RHB (% of batted balls from each side)

Source: fangraphs.com

Sure enough, Teixeira has proven to be remarkably consistent in terms of his approach from each side of the plate. In fact, his spray charts as a lefty and righty have moved in lock step with each other for most of his career. However, there has been a divergence this year. Based on an admittedly small sample, it seems as if Teixeira has become less pull conscious as a right hander this season. Although the abbreviated sample size could be skewing the data, this break from the dominant trend is worth monitoring.

With confirmation that Teixeira has become more pull conscious from both sides of the plate, the next step is to examine how he has performed  in each sub-split. For this analysis, batting average was used instead of on-base percentage to isolate the contributions from batted balls. Also, worth noting is that neither slugging or batting average have been adjusted for the several different home ballparks in which Teixeira has played.

Mark Teixeira’s SLG% and AVG as a RHB

Source: fangraphs.com

As a right handed hitter, Teixeira’s slugging percentage and batting average on balls to center and the opposite field have varied over the years, but there really hasn’t been a significant developing trend. Considering the smaller sample sizes for these two sub-splits, the fluctuations are understandable. More relevant, however, is his performance as a right handed pull hitter, and in this regard, both Teixeira’s slugging and batting average have remained fairly constant.

Mark Teixeira’s SLG% and AVG as a LHB

Source: fangraphs.com

As a left handed hitter, Teixeira has seen a general decline in performance. Most significantly, his batting average and slugging percentage on balls hit to the opposite field have plummeted since 2007. At the same time, his rates on balls to the pull field and up the middle have also gradually fallen off, although this year has seen a resurgence in the latter.  Using 2007 as a starting point can be a little misleading, however. After all, that season appears to be more of an outlier. So, when we remove it from the timeline, what really stands out is the precipitous decline that started to occur last season.

What could explain this consistent decline in Teixeira’s at bats from the left side? Around this time last year, I tried to answer the very same question and leaned toward the possibility that a combination of shifting defenses and changing wind patters at the new Yankee Stadium may have forced to Teixeira to alter his swing in such away as to diminish the quality of his contact. With a lot more data now available, we can better examine this dynamic by not only considering where his balls have landed since becoming a Yankee, but also how they got there.

Mark Teixeira’s HR/FB Rate and FB% as a LHB

Source: fangraphs.com

Mark Teixeira’s GB% and LD% as a LHB

Source: fangraphs.com

There are a couple of trends that have developed during Mark Teixeira’s time as a Yankee. The first is he is hitting more fly balls as a left hander, but fewer are leaving the ballpark. At the same, Teixeira has produced increasingly fewer line drives, particularly to the pull side. This combination of lesser contract and fewer fly balls landing over the wall has conspired to diminish Teixeira’s effectiveness as a left handed hitter.

Mark Teixeira’s Home/Road Splits as a LHB

Source: mlb.com

If Yankee Stadium has been the reason for Teixeira’s relative struggles as a left handed hitter, it should be evident in his home/road splits over the past three seasons. Unfortunately, the data doesn’t cooperate because his statistics as a lefty have suffered regardless of venue. However, that doesn’t mean Yankee Stadium hasn’t had an impact. It’s still possible that by altering his swing for the Bronx, Teixeira has carried over the same mechanics on the road. Another possible explanation is that after learning how to counteract Teixeira at Yankee Stadium, pitchers may now be applying those lessons on the road. This would explain why Teixeira performed so well at home in 2009, but has lagged since then.

What ever the reason, Mark Teixeira’s profile as a hitter has changed while in pinstripes. At this point, it hasn’t diminished his overall value because the first baseman has remained very productive. A lull in 2010, however, does serve as a warning. In that year, Teixeira’s right handed swing wasn’t able to compensate for his growing flaws from the left side.

In some ways, Teixeira’s progression is reminiscent of the transformation of Jason Giambi, who morphed from a batting champion into an all-or-nothing slugger by the end of his Yankees career. Is Teixeira headed toward the same fate? Although the numbers do seem to be trending that way, there are several differences to consider. The first, and most obvious, is that as switch hitter, Teixeira has the ability break away from his limitations as a lefty at least part of the time. Secondly, Teixeira is a much better athlete, so he may be able to make a future adjustment. Finally, even if Teixeira continues to evolve into a one dimensional slugger, that is still a valuable commodity when combined with Gold Glove defense.