When Xander Bogaerts was climbing the prospect rankings back in 2013, he was billed as an offense-first shortstop, a guy who would probably end up growing out of the position early in his career, but would have the power to become a top flight third baseman. In summarizing their write-up as the Red Sox top prospect after the 2013 season, Baseball America wrote that Bogaerts should develop into “a likely peak of 25-plus homers a year in the middle of the lineup.” In other write-ups, they noted his “plus plus raw power”, and the questions about his value were almost always tied to his defensive abilities.

Bogaerts, now 24, is coming off back to back +4 WAR seasons, and as a 24-year-old, he’s established himself as one of the best young players in baseball. But he’s also turned himself into something like the complete opposite of what he was billed to be as a prospect.

Bogaerts, right now, has a 113 wRC+, the same mark he put up last year. But instead of building off his 21 home run season, Bogaerts has instead gotten to that mark by turning himself into the east coast version of Joe Panik.

In his first 96 plate appearances of the year, Bogaerts has racked up 29 hits, but 26 of them have been singles. He has two doubles and a triple, but has yet to hit a ball out of the park, and so while he’s hitting .330, he’s slugging just .375. And even that might be overstate his 2017 power levels.

Bogaerts has 78 balls tracked by Statcast this year. Of the 133 players with 70+ tracked batted balls this year, Bogaerts ranks 127th in average exit velocity on balls in the air. Here are the six players who rank below him: Dee Gordon, Jorge Polanco, Erick Aybar, Jarrod Dyson, Billy Hamilton, Jose Peraza. Bogaerts is hitting the ball with the kind of authority that makes you something like an offensive zero. And even though he’s making more contact, it’s really hard to produce at a high level with this kind of contact.

MLB rolled out an expected wOBA calculation as part of their recent Baseball Savant update, so you can search for an xWOBA leaderboard from their site now. They take the expected outcomes on balls in play from the Statcast data (and add in actual walks, hit by pitches, and strikeouts) in order to give an idea of what a player’s performance would look like if their outcomes had matched the probabilities based on their exit velocity and launch angle.

191 players have 75+ ABs this year. By MLB’s xwOBA, Bogaerts ranks 180th, with an expected .257 wOBA. Gordon and Dyson are right behind him at 182nd/183rd, while Polanco’s not far ahead, at 173rd, and then Aybar/Hamilton are at 166th/167th. Peraza, with a .280 expected wOBA, has the best mark of the seven lowest air-ball exit velocity guys, ranking 160th of the 191 players by xwOBA.

As a group, these seven are actually hitting .250/.306/.320 this year, with a .279 woBA/71 wRC+. That’s with Boagerts and his 113 wRC+ included. If you don’t hit the ball hard in the air, you don’t produce offensively. Bogaerts is currently getting good results out of a bad process. He’s hitting too many ground balls — his 59% GB% is a career high — to go along with his weak air ball contact, and his long history of hitting too many infield flies has carried over as well, adding some automatic outs to the ledger. This is not the batted ball profile of a guy who should have an above average batting line.

Even during his strong 2016 season, there were some reasons for concern. As Tony Blengino noted in his write-up on AL shortstops this winter:

Like many Red Sox regulars, Xander Bogaerts is helped greatly by Fenway Park. While his average fly-ball exit speed of 90 mph is quite solid, he hit a heaping helping of 85-95 mph flies that are outs in most parks. A bunch of those are wall-scrapers or better in Boston. His Unadjusted Fly Ball Contact Score of 124 is marked down significantly to 90 for context. In a development that has nothing to do with Fenway Park, Bogaerts hit .316 AVG-.337 SLG on grounders (172 Unadjusted Contact Score), though his grounder authority supported only a 118 mark. I’m also a bit concerned about his very high pop-up rate vis a vis his ordinary fly-ball rate. Love the youth, love the low K rate, but at this stage Bogaerts doesn’t quite belong in a Correa/Lindor discussion.

To Tony’s point, Bogaerts’ career splits show the way that he’s benefiting from Fenway Park, as he’s running a .136 ISO/.364 BABIP at home and a .106 ISO/.313 BABIP on the road. Drop the power and take the air out of his BABIP, and he goes from a .357 wOBA/117 wRC+ guy at Fenway to a .298 wOBA/87 wRC+ when the team isn’t playing in Boston.

Now, it’s never as simple as just looking at a player’s home/road stats and determining that his road numbers are what he really is, with the difference being the park factor. Bogaerts knows he’s playing in a park with a wall that rewards short flies to left, so it’s very likely that he, like every other right-handed hitter in Boston, has worked on his game to take advantage of the Green Monster. If Bogaerts played in a different park, perhaps he’d do things differently, and his results would change as well.

While playing in Boston, making a lot of contact and hitting a bunch of balls off the Green Monster isn’t a bad plan; this is basically how Dustin Pedroia came to be one of the league’s best players for the last 10 years.

But this is a very different player than the one Bogaerts looked like as a minor leaguer, and while he’s cut his strikeout rate down to Pedroia-esque levels so far this year, he’s still not making Pedroia-esque contact, and he probably can’t keep his K% at 10% with an 86% contact rate. If the strikeouts go up, Bogaerts is going to need to hit for power to offset them again.

And clearly, he should be able to. He averaged 92.5 mph on his balls in the air last year, roughly at league average, so having Dee Gordon’s batted ball authority isn’t the norm for him. He had 56 extra base hits last year. This is a kid who ran ISOs over .200 in the minors as a teenager, which is quite rare indeed. Scouts weren’t making up the idea that he had power.

But we’re now 2,113 plate appearances into Bogaerts career, and he has an ISO of .122. Instead of becoming Carlos Correa, justifying his existence at shortstop with thundering rockets off the bat, he’s become a solid enough defensive shortstop who hits like a guy who plays shortstop.

And yet, for all the issues we’ve just discussed, the reality is that Bogaerts has put up +9.7 WAR since the start of the 2015 season, ranking third among shortstops over the last couple of years. He’s a 24 year old middle infielder with a career wRC+ of 102, plus adds a bunch of value on the bases. And there’s still reason to think that there’s some power in there somewhere, even if he’s not tapping into it right now. Add even average power to the rest of his game and he’s a terrific overall player.

Bogaerts probably won’t keep slapping the ball like he has in the first month of the season, and perhaps his experiment in making more contact will lead to a better balance of batted-ball authority along with a reduced strikeout rate. But while Bogearts remains a good player, he’s a very different good player than I ever expected him to become, and it remains a bit confusing to see a guy who was hyped as a slugger spend a month hitting like Dee Gordon.