This rookie is doing damage at the plate

Kyle Lewis knows how to make an entrance.

The Mariners’ No. 10 prospect showed that last September, when he homered in each of his first three Major League games, and six of his first 10. He is showing it again early in the 2020 season. After a power-packed Summer Camp, he homered in both of the first two regular-season games in Houston -- including a 438-foot blast off Justin Verlander on Opening Day -- and smacked a go-ahead two-run single in the eighth inning of the third contest.

In seven games through Thursday, Lewis is batting a scalding .448/.500/.655, with multiple hits in five straight contests. He owns a career slugging percentage of .610 and is one of 13 players on record to go deep eight times in his first 20 games.

That won’t last, of course. We’re still talking about just 107 plate appearances in total. Baseball history is filled with hitters who started hot only to be left in the dust when the league inevitably adjusted.

But there are reasons for Seattle fans to be excited about Lewis, beyond the gaudy results thus far. The underlying numbers suggest a special type of hitter, albeit one who also faces questions about a highly visible weakness.

Here is a look at what makes the start to Lewis’ career so eye-popping, and what to watch for as he tries to make it stick.

Launch it like Lewis

Lewis has shown a capacity for elite exit velocity, with five of his home runs coming off the bat at 105 mph or harder, including the 110.9 mph shot off Verlander on Opening Day. His career hard-hit rate of 41.7 percent is solidly above average (around 37 percent), and FanGraphs reported that it was 53 percent in the Minors last season.

What stands out even more is how Lewis generates lift. Six seasons into Statcast’s tracking of launch angle, it’s no secret that driving the ball in the air is how a hitter does damage. But a metric called sweet-spot rate allows us to be more precise. Balls on the ground are rarely extra-base hits, but balls hit too high in the air are usually outs. The sweet spot is the happy medium between 8-32 degrees of launch angle that in 2019 produced a 1.175 slugging percentage and 78 percent of MLB’s extra-base hits.

Entering Thursday, Lewis had hit 45.6 percent of his career batted balls within that sweet spot, the 12th-highest rate out of 220 qualifiers since last Sept. 1. Again, we’re talking about a grand total of 57 batted balls here. But these underlying numbers tell us far more than the raw results.

The list of 11 hitters in front of Lewis on that list includes Ronald Acu?a Jr., Yoán Moncada, Kris Bryant, Mookie Betts, Nick Castellanos and 2019 American League home run champ Jorge Soler. The MLB leader with a 43.8 percent sweet-spot rate in ‘19 was none other than Mike Trout.

Hitting the ball in the sweet spot, in and of itself, does not guarantee power. You still have to hit the ball hard -- which Lewis can. Just look at the players with the most barrels -- batted balls with an optimal combination of exit velocity and launch angle -- since Lewis made his MLB debut last Sept. 10. He’s in good company.

Most barrels hit since Sept. 10, 2019
1) Jorge Soler (KC): 14
2-T) Kyle Lewis (SEA): 12
2-T) Eloy Jiménez (CHW): 12
2-T) Kyle Schwarber (CHC): 12
2-T) Corey Seager (LAD): 12
6-T) Bryce Harper (PHI): 11
6-T) Nick Castellanos (CIN): 11
6-T) Nelson Cruz (MIN): 11

When you hit the ball like this, good things tend to follow. Among the aforementioned group of hitters since last Sept. 1, through Wednesday, here is where Lewis ranked in terms of productivity on balls put in play. Expected batting average (xBA) and expected slugging percentage (xSLG) are based on the quality of contact, rather than the actual results.

BA: .536 (2nd, behind Moncada)
xBA: .479 (T-1st with Soler)
SLG: 1.054 (1st)
xSLG: 1.008 (3rd, behind Acu?a, Soler)

Feel the breeze

There is a “but” here.

Notice that in the stat above, we highlighted the words, “on balls put in play.” That’s because getting bat on ball has been a bit of a challenge for Lewis. The 6-foot-4 slugger slugger struck out 29.4 percent of the time in Double-A last year, and that has risen to 38.3 percent so far in the Majors, including 37.5 percent in 2020.

MLB average is 23 percent, and in 2019, only two qualified hitters were at 30 percent or above: then-Mariner Domingo Santana and the Rangers’ Rougned Odor. Neither was especially effective overall.

It’s possible to overcome that sort of sky-high K-rate, but it is difficult. Margin for error is small. Of the 27 individual player seasons with at least a 34 percent K-rate (minimum 400 plate appearances), just 11 have come with a wRC+ that was at least league average (100). And those are the ones who managed to stay in the lineup.

Best offensive seasons with a 34% K-rate or higher
Min. 400 PA
1) Miguel Sanó (2019 MIN): 137 wRC+, 36.2% K-rate
2) Mike Zunino (2017 SEA): 126 wRC+, 36.8% K-rate
3) Miguel Sanó (2017 MIN): 125 wRC+, 35.8% K-rate
4) Joey Gallo (2017 TEX): 119 wRC+, 36.8% K-rate
5) Adam Dunn (2012 CWS): 115 wRC+, 34.2% K-rate

That prompts two questions. Can Lewis cut down those strikeouts? Or, barring that, can he be the rare breed of hitter whose quality of contact is elite enough to be worth all the whiffs?

On the downside, Lewis swings and misses a ton. He’s come up empty on about 40 percent of his swings, one of the highest rates in MLB since his debut, though not out of line with the likes of elite sluggers such as Sanó and Aaron Judge.

What’s interesting about Lewis’ approach in the very early going in 2020 is that he has been far more selective. Here were his swing rates by location, through Thursday:

2019: 47.9 percent overall, 33.7 percent out of zone, 67.9 percent down the middle
2020: 39.3 percent overall, 27.8 percent out of zone, 75.0 percent down the middle

Lewis told FanGraphs’ David Laurila back in March that he felt he had “grown” in terms of determining when to swing.

“I feel I’m better able to make good decisions on pitches in the damage zone,” Lewis said.

Through seven games this season, Lewis has drawn as many walks (three) as he did in 18 games in 2019. The continuation of that trend could do a lot to keep Lewis productive at the plate.

The 11th overall pick in the 2016 Draft out of Mercer (Ga.) University, Lewis missed significant time due to injury early in his Minor League career. Even now, he has only a bit more than 1,300 professional plate appearances, so it would hardly be a shock if he continues to refine his approach as he gains experience

Time will tell. For now, Lewis has put MLB on notice that he is a hitter to watch.