When Red Sox president of baseball operations Dave Dombrowski went on WEEI and said that shortstop Xander Bogaerts (alongside Mookie Betts) was someone he hoped to see in Boston for the long haul, the statement certainly did not surprise anyone. After a somewhat disappointing rookie season, Bogaerts bounced back in a major way in 2015, finishing third in baseball among shortstops in fWAR.
But, after all, this — and more — was expected of Bogaerts when he first arrived in the big leagues in 2013. At the time, he was one of the most hyped Red Sox prospects in the last decade. The distinction of being one of the top-two prospects in baseball, however, did not preclude the 22-year-old from struggling to make the transition to the big leagues.
Bogaerts' struggles during his rookie season are well documented, but they came down to a few glaring areas of weakness. Among the noted areas of strengths for Bogaerts during his ascent through the minor leagues was his ability to drive the ball to all fields. That didn't happen during his rookie season. According to FanGraphs, Bogaerts pulled 46.9 percent of batted balls in 2014, while only hitting 19.3 percent the other way. On a related note, he also struggled to hit breaking balls, seemingly amplified by his desire to pull the baseball. The cherry on top for Bogaerts' bad season was his struggles in the field, where he totaled -16 DRS between third base and shortstop.
After his disappointing rookie year, Bogaerts needed to take a step forward in 2015. Instead, he took a running jump. He went back to his roots, played to his strengths and got rid of the things that slowed him down. The most notable change he made was of course the move to high socks. Because high socks rock. And clearly make players better (correlation always equals causation, as we all know). But let's look at some of his less important changes.
Firstly, Bogaerts made a drastic shift in his approach on breaking balls. In 2014, Bogaerts saw 432 sliders and struck out 40 times on the pitch. In 2015, Bogaerts saw 418 sliders and struck out a total of 26 times. This shift helped contribute to his drop in strikeout rate (23.2 percent in 2014 to 15.4 percent in 2015). Bogaerts also swung significantly less at curveballs, according to Brooks Baseball. After swinging at 42 percent of curves he saw in 2014, Bogaerts bit on just 31 percent in 2015. Unsurprisingly, Bogaerts' whiff percentage on the pitch dropped as well, from 12 percent to 8.5 percent.
Here's something else interesting: Bogaerts began to swing more at pitches towards the bottom and out of the strike zone.
Normally, a development of this sort probably wouldn't bode well for a young player, but the difference with Bogaerts is that he made even more contact. And then the singles came. And then balls started going towards right field And the batting average went up.
Bogaerts' spray chart in 2014 suggested that he significantly favored pulling the baseball. The Green Monster played a major role in Bogaerts' rookie season given his tendency to pull pitches, something he did not do during his rise through the minor league system. Another development, as seen in the zone profile, shows how Bogaerts evened out the swing percentage on pitches on the outer half of the plate with that on pitches inside. In 2015, Bogaerts returned to his ways from the minor leagues, taking pitches on the outer half of the plate the other way. The change in spray chart correlates with the more even swing distribution across the plate.
This visual change in the spray charts moves onto the spreadsheets as well. According to FanGraphs, Bogaerts hit baseballs at 33.8, 34.2 and 32.0 percent towards left, center and right field, respectively; in 2014, he hit baseballs at clips of 46.9, 33.7 and 19.3 to left, center and right field, respectively. So that improvement is massive.
Bogaerts fiddled around with his mechanics a lot in 2014, moving between a closed stance toe tap and a leg kick. He settled on an open stance with a big leg kick in 2015, which remained consistent throughout the season.
Let's take a look at the major jump in fielding Bogaerts made. Errors don't tell the whole story when trying to grasp how well someone can field, but Bogaerts reduced his errors from 21 to 11 in 2015 all the same. The improvement defensively is harder to quantify, but a glimpse at some video reveals some insight.
Here are two plays emblematic of Bogaerts' overall defensive struggles in 2014.
In the throwing error, Bogaerts throws the ball away after double pumping. While the runner on second base clearly needed attention, Bogaerts paid too much of it in this situation and was unable to complete the throw. In the second error, the ball bounces off of Bogaerts as a result of messy footwork that has him taking his momentum away from first base and has him not set himself up to cleanly field the grounder, despite getting to the ball on time. Bogaerts improved in all of these areas in 2015.
The footwork is smooth and the throw is strong, confident and accurate.
While Bogaerts didn't display the prodigious power in 2015 that made him an uber-prospect zipping up through the minor leagues, there are explanations for that. Minor injuries played a role in Bogaerts being unable to drive the ball over the fence, according to a source. But those injuries healed by the end of the season and Bogaerts' power began to come out of hiding, which was on display with the shortstop's three home runs in the last month of the season, a total that equaled his power output from the entire first half. Don't give up on Bogaerts' power just yet.
One thing to look out for in terms of regression for Bogaerts is the BABIP. While Bogaerts maintained a BABIP around .360 through the minor leagues, he managed a .372 mark in the majors in 2015. This high a number generally proves unsustainable, and suggests Bogaerts might take a step back in 2016 if he can't compensate with increased power. Not necessarily to the .296 BABIP mark in 2014, but a step back nevertheless.
The most encouraging thing about Bogaerts, however, is that there was improvement, and not in a fluky way. That ability to adjust is something that marks and defines a big leaguer and that Bogaerts identified areas of weaknesses from 2014, made an effort to improve for 2015 and then displayed significant jumps in ability on the field as a direct product of the work suggests a ceiling. at the very least, of a perennial All-Star.
But we all know that the real reason for the jump in performance is the high socks. Because high socks rule all.