The old Thompson has disappeared without a Trayce

First, let’s start with what we knew about the real Splash Brother heading into this season. If you squinted hard enough, you could see a big, athletic outfielder with some speed, power, and defense in the outfield. However, you didn’t have to bring out the binoculars to see his on-base percentage, which never exceeded .329 at any extended stay at any level in the minor leagues, or to see his strikeout rate, which sat comfortably above 20 percent for most of his minor league career.

He was a tweener profile that probably didn’t have enough range to be a regular in center field and didn’t have enough bat to profile in a corner. Oh, and he was already 25 years old, having spent seven seasons in the minors. Does this sound like an interesting player to you? Sure, maybe it interests you, but he isn’t a particularly valuable piece. And his value was somewhat demonstrated this offseason, as Thompson was dealt from the White Sox to the Dodgers in a three-team deal that sent Todd Frazier from Cincinnati to the Sox.

However, he wasn’t the main piece of his return; that honor belonged to flamethrower Frankie Montas, who is primed to make his Dodgers debut in the near future, possibly in the rotation. It’s like going to a steak restaurant; Montas is the steak that the Dodgers ordered, and Thompson is just the mashed potatoes that came with it. Do the mashed potatoes interest you? Would you rather have mashed potatoes than no mashed potatoes? Sure, to both questions, but that isn’t really the reason that you came to this restaurant. However, this is just how it appeared to the world outside of the Dodgers’ front office, and it’d be disingenuous to imply that Andrew Friedman and company lucked into Trayce Thompson. They somehow knew that, mid-dinner, the mashed potatoes they ordered were going to transform into an even tastier steak than the main course.

Thompson's about 30 plate appearances shy of qualifying for the batting title, but among NL players with at least as many plate appearances as his 159, only eight sport a higher wRC+. His mark of 147 this season bests those of Paul Goldschmidt, Anthony Rizzo, Bryce Harper, and Nolan Arenado, just to name a few. If you want to talk about tangible impact, Thompson already has multiple walk-off homers for a team that has been surprisingly devoid of offense this year.

Now, it’s clear that he’s been good, but the more pertinent question is whether it’s sustainable or not. In his first full season in the majors, Thompson is actually sporting the best walk-to-strikeout ratio of any stop in his professional career. He’s walking at an excellent rate of 11.3 percent while keeping his strikeout rate manageable (22.0 percent), especially for the power he’s been producing.

More importantly, the peripheral plate discipline stats all back up this growth. Thompson sports a ridiculously low chase rate of 19.7 percent. Among all qualifiers last season, that mark would’ve been the second best in all of baseball, behind only the dean of plate discipline himself, Joey Votto. Among players with at least 150 plate appearances this season, it places Thompson 12th. However, he has a higher swing rate than all of the 11 hitters ahead of him. That’s extremely notable because the goal of hitting is to swing at strikes and take balls; it isn’t to take strikes and balls. Many hitters just produce crazy-low chase rates because they simply don’t swing at anything; however, Thompson has been both aggressive and disciplined at the plate this year. He sports both a lower chase rate and higher swing percentage than noted discipline master Matt Carpenter, who probably doesn’t scratch his own scabs or eat raw cookie dough.

Plate discipline and high strikeouts were the main concerns with him going into the season, and he has managed to turn one of those into a strength. The improved approach has helped him better tap into his power, getting better pitches to hit. It shows in his stat line, as he’s posted a slugging percentage of .546 and an isolated slugging of .270. As icing on the cake, Thompson is doing all of this with just a .301 BABIP. Almost every one of the other hitters with a similar offensive production level owns a BABIP mark much higher.

As someone who A) hits the ball hard, B) has as much speed as he does, and C) hits as many ground balls as he does (55.7 percent), his BABIP should be much higher and will probably inch up in the near future. However, this ties into the biggest downside of his stat line: because of all of those ground balls, that also means he isn’t hitting as many line drives and fly balls. Sure enough, he sports a HR/FB rate of 30.3 percent, which is quite unsustainable. Yes, his power is real, and he’s been hitting home runs out to all parts of the park. But for reference, no qualifier possessed a HR/FB percentage that high last season.

To recap, if Thompson simply maintains the changes that he made this season and keeps doing what he’s doing, the plate discipline will remain excellent, and his BABIP should go up while his home run rate goes down. His overall production is 47 percent above league average, so he should comfortably be a well-above-average hitter.

Possibly the most exciting part about this breakout is that it has come without any signs of platoon splits, and as Dave Roberts has plugged him into the starting lineup everyday Thompson’s production has improved. He is quickly shedding the label of lefty-masher platoon outfielder, and the Dodgers have announced that Thompson will continue to play every day even when some of their other outfielders get healthy.

As someone who projects as an everyday outfielder going forward and comes with five years of team control plus this year, Thompson was an amazing heist. A good argument could be made that he’s the most valuable piece moved by any team in the three-way trade.

However, besides the inevitable power regression, there are a couple of other dark clouds hanging over that could put a damper on this celebration. First of all, for someone who came into this year with defense being his most consistent and valuable trait, Thompson has been quite awful. He’s put up a UZR of -22.5. While it’s still early for defensive stats like that, when you’re that negative as late as June, it has to say something. And as someone who watches Thompson play every day, I can tell you that his routes in the outfield are just horrendous. Like, his routes are some of the worst of any outfielder I’ve ever watched. Now, hopefully this is something that can be taught or learned through experience. He still possesses the range and other physical tools to be a plus in the outfield.

The other negative has to do with the projection systems. Despite all of the offensive growth, both ZiPS and Steamer are in eery agreement on his forecast, projecting his rest-of-season wRC+ to be 97 and 98, respectively. Maybe Thompson really has changed, but there have simply been too many years of mediocrity in the minor leagues, and now he’s facing much tougher competition in the Show.

Still, for a team struggling to put runs on the board like the Dodgers, there is no reason not to run Thompson out there every day and see whether or not you really have a star on your hands. And make no mistake, Thompson’s current production unequivocally equals a star. The only question is whether or not he can keep up his current production, and the stats seem to point to yes.

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Austin Yamada is a contributing writer for Beyond the Box Score.