Today is Kyle Lewis’ birthday. Now, I don’t know that because I follow him closely, or because we’re friends, or because of any reason other than simply wondering when he turned twenty-five. Turns out, that’s today. The first draft pick of the Jerry Dipoto-era, Lewis came to Seattle a bit older as far as draftees come, with a highly-polished skillset that, if you squinted, looked like a guy who could play league-average-ish centerfield and provide a plus bat. That’s an incredibly useful player. He instantly became the most exciting prospect in the Seattle system. We all know the rest of that timeline, the freak injury and its recurrence, and the subsequent delay in development and ascension through the ranks. All leading to this: Kyle Lewis only has 75 plate appearances in Major League Baseball and is twenty-five.

Those 75 plate appearances are what have us dreaming of the high ceiling we saw for him back in 2016. In his short, reduced role due to injury concerns, Lewis became a bizzarro version of himself at the plate. Either by choice or force, his plate discipline disappeared in exchange for a massive power surge. If Lewis managed to keep his 2019 rate of bashing dingers in a full, 600 PA season, he’d hit fifty home runs. That has only ever been done in a M’s uniform by Griffey. The power, especially to the opposite field, is incredibly encouraging. It’s a reason to be excited by Lewis. His swing is long, it has a ton of barrel through the zone, and he gets big extension on his long frame. He will probably always crush outside pitches with his swing’s current iteration.

The other side of the coin is a little less savory. While pacing for 50 HR’s in 600 PA’s, Lewis also paced nearly 230 strikeouts and a meager 24 walks. Pete Alonso was the only guy in the entire league to surpass fifty home runs, and he managed 72 free passes while striking out 183 times. Alonso also did this in nearly 700 plate appearances. Christian Yelich was probably the nearest player to pacing 50 home runs over 600 PA’s and still would have fallen a few short had he reached that many trips to the plate. We’re sort of swimming in uncharted waters here, especially due to the extremely small sample and the bouncy-ball currently in play. It’s hard to say exactly how valuable this skillset is when you’re talking about a K rate and a HR rate that wasn’t seen in the MLB last year. Nobody with qualifying PA’s had over 190 K’s at the plate in 2019.

So, what could a potential full-season of Kyle Lewis look like? First, you’d hope the plate discipline returns a bit. On his way up the system, Lewis ran a fairly consistent 9-10BB%. Having that drop to 4% over an entire season while striking out 38% of the time would be Mike Zunino 2015 levels of ugly. However, how much different does that Zunino 2015 season look if instead of bashing 11 bombs in 400 PA’s, Zunino hits 33? Does a more moderate version of Lewis’ 2019 play in a corner outfield spot with average defense? It likely does. 

Regressing to the mean a bit in K%, BB%, and home run pace, he could potentially look something like 2019 Cole Kalhoun. Lewis would have to return much closer to his plate discipline numbers in the minor leagues, all the while accounting for a likely loss in power. I’m fairly comfortable watching Lewis and seeing him hit around thirty home runs in a full season with current conditions. I’m also mostly comfortable imagining Lewis with a wRC+ of 110. Kalhoun and Lewis received nearly identical defensive ratings by Fangraphs. Cole Kalhoun was an above average player in 2019. I think we’d all call that a success given Lewis’ injury status just a year ago. 

On the flip side, if Lewis doesn’t improve upon his plate discipline, we have 2019 Randal Grichuk. Grichuk’s value in 2019 was nearly replacement-level, due in large part to terrible defensive numbers that we likely wouldn’t see from Lewis in a corner spot. However, Grichuk also provides a model for a 30+ home run guy who doesn’t walk. His wRC+ of 90 while providing significantly below-average defense has some potential modeling relative to Lewis. Grichuk was bad in 2019 both in the field and at the plate. This isn’t Lewis’ destination, but it’s a fork in the road if he totally abandons his previously fine monitoring of the strike zone.

A last, aspirational comp for Lewis would be 2016 Charlie Blackmon. Here we’d have an outfielder who walks just a tick more than Lewis in 2019, strikes out at half the rate, and frankly, hits for average well-above Lewis in 2019, all while slugging 30 bombs. Both players would receive similar defensive rankings in their respective positions, all totaling a nearly 5 fWAR player. Lewis has a lot to show to get to Blackmon’s 2016. There are other paths for him to achieve 5 WAR without having to literally half his K%, but it’s an important step if Lewis is going to reach a full season of corner outfield above 2 WAR.

Ultimately, attempting to forecast Lewis is extremely difficult due to the very small sample of data available. There is no doubt that the power is legitimate and big. Defensively, we’re mostly aware that Lewis can provide league-average defense in a corner. The plate discipline questions are wide open and likely determine his ultimate value on a major league roster. Has the league adjusted to Lewis? Probably not. However, he did see a large number of sliders in 2019. This pitch is likely going to be the one he’ll have to adjust to, based off his long, extended swing. How Lewis manages that is what I’ll be watching.