What’s behind Kenta Maeda’s early season struggles?

John Foley

Photo: (AP Photo/David Dermer)

One of the more surprising stories from the Minnesota Twins’ poor April is the ineffectiveness of starting pitcher Kenta Maeda. Through five starts, Maeda -- last season’s AL Cy Young Award runner-up -- is 1-2 with a 6.56 ERA, 1.76 WHIP, and .356 opponent batting average allowed. Already, in only 23.1 innings pitched, Maeda has allowed just one fewer run (19) and four fewer hits (36) than he did over last season’s 66.2 innings pitched (20 runs, 40 hits in 2020).

So, what’s going on? Whenever a pitcher is struggling, there are a few things I like to check out. Let’s dig into the data to see if we can pinpoint the issue.

Velocity and Movement

The first area I tend to check is the velocity and movement profiles of the pitcher’s pitches. Is Maeda throwing as hard as before? Are the pitches (especially offspeed pitches) moving as much as they had previously? Major League Baseball has invested heavily in optical tracking technology, called Statcast, in recent years. Thanks to that investment, nearly everything that happens on a baseball field is logged and measured.

Using this data, available at baseballsavant.mlb.com, we can compare Maeda’s average velocity by pitch type, season over season, as shown in the table below:

Data sourced from baseballsavant.mlb.com

There’s really not much difference. His average 4-seam fastball velocity is down a little bit from last year, but not significantly so. It’s also possible that the cold, early season weather is playing a factor in that number. All the other pitches are almost exactly in line with last season, except for the curveball. That pitch is infrequently used (2.7% so far) and Maeda intentionally worked on slowing it down in the offseason. It doesn't seem like there is anything notable going on here.

How about the movement profiles of his pitches? The scatter plots below are from the catcher’s point of view (imagine Maeda was throwing the baseball to you) and the vertical line bisecting the chart implies a straight pitch with no horizontal movement. The top of the chart implies a pitch with no vertical movement. I’ve put Maeda’s 2020 movement and 2021 movement side by side:

Data sourced from baseballsavant.mlb.com

What we find here is somewhat counter-intuitive. The movement profiles on his four-seam fastball, sinker, and split-finger changeup are basically the same as last year. His slider and curveball are both showing slightly more movement than they had last season. That’s surprising, given his overall results this season. More movement tends to be harder to hit and should help improve his results. It doesn't seem like there is anything in the movement data that would indicate why he is struggling.

Pitch Type Mix

After looking at velocity and movement, I like to check to see if a struggling pitcher has changed how they are deploying their pitches. Has anything notable changed in Maeda’s pitch mix?

Data sourced from baseballsavant.mlb.com

A few things are worth noting here. First, Maeda continues to rely heavily on his slider. He’s upped his usage of that breaking ball slightly over last season’s already high rate. His four-seam fastball and sinker are both being used slightly more than last year, at the expense of his split-finger changeup and cutter.

It is also very early in the season. The deviations we are seeing compared to last season could just be random noise, instead of something intentional. It's hard to know for sure.

At any rate, the approach with his pitches mostly seems similar to last year. He’s still offering his slider as his primary pitch, mixing two fastballs essentially the same as he was, and mixing in changeups for about a quarter of his pitches. I don’t see anything especially noteworthy here that would explain his poor performance.

Command & Control

So, it seems Maeda’s pitches are basically the same and he’s deploying them in a similar manner. That leaves the location. Is he throwing his pitches in spots that make them easier to hit?

Again, thanks to Statcast, we can explore this question. Below you’ll see two heatmaps from baseballsavant.mlb.com of the location of Maeda’s pitches. The first is from 2020 and the second is so far this season:

Data sourced from baseballsavant.mlb.com

Data sourced from baseballsavant.mlb.com

Here, we might have found our culprit. The plots make it clear that Maeda has thrown his pitches higher in the strike zone compared to last season. Like before, these charts are shown from the catcher’s perspective. You can see the location of Maeda’s pitches has drifted away from the nice, tight, low spots from last year. Instead, he’s missing with his pitches over the plate, up in the zone, and to his arm side (inside to a right handed batter, to the reader’s left). Misses in this type of pattern are clear signs that a pitcher’s mechanics are out of whack.

Pitches in those 2021 locations are also much more hittable than the ones he threw last year. That bears out in his numbers. He’s allowed 7 home runs to 112 batters faced already this season after giving up 9 homers to 248 batters faced all of last season. Not surprisingly, those home runs have come on pitches that have missed up, in the middle of the plate, and to his arm side:

Data sourced from baseballsavant.mlb.com

Four of those homers have come from sliders and batters have hit .386 and slugged .773 against Maeda’s primary pitch. Last season, batters hit just .216 and slugged .466 against Maeda’s better located sliders. The other three 2021 home runs have come from four-seam fastballs and batters have hit .400 and slugged .850 against that pitch so far this season. Last season, the numbers against that pitch were an incredible .086 batting average and .114 slugging percentage. Clearly, the change in location is having an impact on Maeda's results.


Lastly, it’s worth taking a look at Maeda’s luck. In a small sample of just one month’s worth of pitching, it’s entirely possible that he’s experiencing some bad fortune that will likely improve over time. There are a handful of stats that I like to check on in this area.

The first is batting average on balls in play, known as BABIP. All pitchers allow pitches to get hit into play and then rely on their defensive teammates to convert those into outs. Depending on how hard the ball is hit, where it is hit, and how the defenders are positioned, how well those batted balls are turned into outs can fluctuate quite a bit. In Maeda’s case this season, he’s experienced an overly high percentage of batted balls in play falling in for hits, instead of turning into outs. Per FanGraphs, Maeda’s BABIP is .372, the second-highest figure of any pitcher with at least 20 innings pitched, and dramatically different from last season’s .208 and his career average of .278.

Another stat that can indicate luck is home runs to fly ball rate, shortened to HR/FB. The league average HR/FB is around 13% so far in 2021. Maeda’s rate is 26.9%, an extremely high rate that means that more than a quarter of the fly balls he has allowed have gone for home runs. By this measure, Maeda has the 6th-highest rate among pitchers who have thrown 20 innings. For comparison, last season his HR/FB rate was 18.8% and his career average is 14.2%.


To wrap this up, I think Maeda’s troubles to start 2021 are mostly driven by lagging command of his pitches. He’s missed too frequently in the middle of the plate which has resulted in hard contact and extra base hits, especially home runs. Those hard hit balls on mistake pitches contribute to the high BABIP and HR/FB rates.

If Maeda is going to turn it around and help the Twins’ recover from their poor start to contend in the American League Central, he’ll need to correct his mechanics to more consistently hit his spots lower in the zone. As he heads into a start tonight against Texas, his command will be worth watching closely. If he minimizes his missing up and to his arm side, it will be a sign that he’s making progress and getting closer to being the pitcher we saw last season.

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I analyze and write about the Minnesota Twins. My perspective has been developed from my lifelong fandom of the Twins, collegiate playing days as a pitcher, and graduate education in business and analytics. My goal is to use my experience in baseball and familiarity with its numbers and data to explain, inform, and educate about the events happening on and off the field.

Minneapolis, MN

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