When Xander Bogaerts played in the 2013 World Series as a 20-year-old rookie, it was easy to see the start of a promising career: he was a glove-first shortstop (though he played mainly third base in 2013, ceding short to Stephen Drew) with enough pop and size to eventually be an impact bat. Over the next four years of his career, though, that promise of power remained tantalizingly out of reach. At the end of 2017, Bogaerts’ career line was nearly exactly average (101 wRC+), but the extra-base hits never quite developed as projected. His .127 ISO was in the 19th percentile of batters with at least 2000 PA over that time period, and his slugging was hardly better (.409, 28th percentile).
Now, a league average bat at shortstop is still tremendously valuable. Bogaerts was worth 12.9 WAR over those four-plus years, a 3 WAR/600 PA pace that would make him a starter on virtually every team. Still, you could look at the promise of a 20-year-old Bogaerts, a 6-foot-1 live wire getting important at-bats on the biggest stage, and wonder why he hadn’t tapped into more offense. It had been four years, after all. Surely if he was going to fill out and add power, it would have already happened.
Two years later, that 2017 endpoint looks awfully conveniently timed to fit a narrative. Since the start of the 2018 season, Bogaerts has found another gear. He’s batting a scintillating .291/.366/.526, good for a 134 wRC+, and the power has miraculously appeared, with his .235 ISO ranking in the 84th percentile among qualifying batters. Still only 26, Bogaerts now looks like one of the best players in the game, full stop. The player fans and scouts saw glimpses of in 2013 is finally here.
What did Bogaerts do to tap into his enormous potential? Well, given that his power numbers have spiked across the board while his strikeout and walk numbers have barely budged (18.5% strikeouts and 7.2% walks 2013-2017 versus 18.1% and 10.2% thereafter), it would be easy to say he just started hitting the ball harder. He always looked like he had the potential to do that. A few pounds of muscle here, a little physical maturation there, a smattering of juiced baseball, and warning track power becomes home run trots. Take a look at Bogaerts’ average exit velocity from 2015 (the first year of Statcast data) to now, on all batted balls and also balls he hit in the air: Read the rest of this entry »