Xander Bogaerts has always been pretty good.
He eclipsed 4.5 WAR in both 2015 and 2016.
In the 2013 playoffs, before he’d even used up his rookie status, he slashed .296/.412/.481.
But last year he ascended to a new level of production at the plate, a transformation that’s lasted into 2019. Here’s his wRC+ by season. Keep in mind that 100 is a league-average hitter.
Bogaerts, who was below-average compared to the rest of the MLB in two of his first four seasons, has more than doubled even his best pre-2018 season, relative to the average.
And, to be sure, his WAR has reflected this.
But the more impressive thing is, Bogaerts’ WAR could be even higher, if the shortstop position as a whole wasn’t in the midst of an overall upward shift in production.
WAR does not view all offensive performance equally. It compares hitting based on position, under the logic that bats are easier to come by at certain positions than they are at others. Because of this nuance, Bogaerts’ 141 wRC+ this year is measured by WAR as much more valuable than, say, Carlos Santana’s 142 wRC+. Santana plays first base, and while he’s a valuable piece of the offense, strong-hitting first basemen are more abundant than strong-hitting shortstops.
Here’s the median wRC+ among qualifying shortstops, by season, since Bogaerts’ rookie year.
The improvement isn’t as striking as Bogaerts’ personal climb, but in the context of an entire group of position players, it’s significant. The median shortstop in 2019 is 10% better at the plate than the median shortstop was in 2014, and 20% better than his 2015 comp.
And to be clear, there hasn’t been some shift in Bogaerts’ defensive value that’s holding back his WAR. His defensive runs above average—the metric FanGraphs presents as its most all-encompassing defensive verdict, has stayed relatively constant after a rough rookie year:
Bogaerts’ increasing value comes in a context in which it’s harder to impress WAR as a shortstop. He was at the front end of a string of strong-hitting shortstop debuts, with Javier Báez following him in 2014, Francisco Lindor and Corey Seager making their big-league clubs in 2015, and Trevor Story entering the league with a bang in 2016. His peers are better than they were in 2014, but he’s managed to improve at a rate clearly faster than that of the position as a whole.
So what’s Xander Bogaerts doing that’s making him so much better?
He’s hitting for power.
A strong contact hitter in 2015 and ’16, seasons in which he won Silver Sluggers while averaging 14 home runs a year, Bogaerts’ has kept cranking out hits, but has increased the value of those hits. He slugged 23 home runs last year in only 136 games, and he’s on pace to just miss 30 this season. His doubles are up as well.
Here’s Bogaerts’ ISO—the gap between batting average and slugging percentage—by year:
And what’s driving the power increase? Well, he’s healthy, for one, after playing through a wrist injury over much of 2017 after an unfortunate hit by pitch. He’s also getting older, turning 26 last October, an age at which players are often rounding into form.
But there’s more than that. Yes, Bogaerts is hitting the ball harder in general:
But he’s also hitting it in the air more, a tendency that works well pretty much everywhere in baseball right now, but is especially beneficial to a right-handed hitter playing half his games in Fenway Park, where the Green Monster can turn what might be a flyout elsewhere into a double or a home run:
Bogaerts has adapted to his surroundings—his competition, his ballpark, the state of the game—and the result is a shortstop who, to date, has been this season’s most valuable infielder. Shortstops are getting better. Xander Bogaerts is getting better yet.
