This year was going to be different for Seattle Mariners starter Yusei Kikuchi. At least that’s what we thought heading into the regular season. Revamped mechanics, increased fastball velocity, and a new pitch fueled expectations he’d rebound from a frustrating rookie season. Instead, Kikuchi remained an enigma.

Why Kikuchi continued to be a mystery after two MLB campaigns is perplexing. Before arriving in the Emerald City, the talented 29-year-old performed well during eight seasons in Nippon Professional Baseball (NPB). That said, past successes are irrelevant at this point. How he performs in 2021 will determine his long-term future with Seattle. You see, an expensive decision awaits Kikuchi and the Mariners after next season.

Money Matters

Kikuchi, who receives $16.5 million next year, has a unique set of contract clauses. Per Baseball Prospectus, the Mariners must determine within three days after the 2021 World Series whether to exercise their option on Kikuchi. Normally, options cover one year. However, his includes four years through the 2025 season. It’s a take it or leave it deal for the team – nothing or all four years valued at $66 million.

But there’s more.

If Seattle declines its option, Kikuchi has until five days after the Fall Classic to exercise a player option for 2022 paying him $14.5 million dollars. If both parties decline their respective options, he becomes a free agent.

With so much resting on how Kikuchi performs next year, let’s dig into his 2020 stats and attempt to determine why such a talented arm under-performed expectations for a second consecutive season.

Strides Were Made, But…

It’s not as if Kikuchi’s numbers were horrible. Other than ERA and walk rate, his stat line actually showed considerable improvement.

Yusei Kikuchi's First Two Seasons
ERA
WHIP
AVG
wOBA
HR%
BB%
SO%
2019
5.46
1.515
.295
.368
5.0
6.9
16.1
2020
5.17
1.298
.238
.299
1.6
10.3
24.2
MLB*
4.46
1.300
.247
.320
3.7
8.3
22.9
* For Starting Pitchers

Encouraging numbers aside, anyone watching Kikuchi’s nine starts know they were an assortment of underwhelming outings with a few strong performances mixed in. After a difficult season debut, he rebounded with a 6-inning, 9-strikeout outing. Then came his next two starts – a combined 10.1 innings, nine earned runs, eight strikeouts, and five walks.

Hence, the term “enigma.”

At this point, fan frustration with Kikuchi is understandable. Some may see a 5-plus ERA for a second consecutive season and wonder how such an inconsistent performer became the second highest paid Mariner behind Kyle Seager and the most expensive free agent signing during the 5-year tenure of GM Jerry Dipoto.

Difficulties With RISP

Kikuchi’s splits indicate a significant reduction in positive outcomes with men on base (MOB). More specifically, runners in scoring position (RISP). It’s worth noting avoiding damage with RISP is problematic for any pitcher. The MLB-average ERA for this situation was 12.22. Still, Kikuchi’s 22.41 ERA was the highest among 87 pitchers facing at least 45 hitters with RISP.

Kikuchi Struggled With RISP In 2020
PA
ERA
AVG
OBP
SLG
Total
194
5.17
.238
.314
.366
No MOB
111
0.68
.198
.270
.297
MOB
83
11.07
.296
.373
.465
- 1B only
36
1.69
.265
.306
.471
- RISP
47
22.41
.333
.435
.472

Obviously, Kikuchi’s dreadful numbers with RISP are worth exploring, particularly when you consider those 47 plate appearances represented 22.6-percent of the total batters he faced in 2020. However, assessing him solely with conventional stats, like ERA, would be unwise.

His High ERA Is Deceptive

ERA isn’t an ideal measurement of a pitcher’s performance or talent since defense and ultimately the official scorekeeper can affect it in a good or bad way. Let’s review a pair of instances when questionable glove work and scorekeeping negatively affected Kikuchi’s ERA.

The first play in the following video is a ball put in play by Houston’s Alex Bregman, which drove in José Altuve from first base. Bregman received credit for a double and an RBI, although left fielder Tim Lopes probably should’ve caught the ball for the third out of the inning.

After the Bregman double, we see another questionable two-bagger leading to an earned run. This time, Arizona’s Eduardo Escobar hits a fly ball with an 82.3-MPH exit velocity to Mariners right fielder Phillip Ervin, who misplays it allowing Josh Rojas to advance from second to third base with Escobar taking second base. Next, notorious Mariners killer Kole Calhoun drives in Rojas with a sacrifice fly increasing Kikuchi’s ERA.

The play sequence in Arizona was particularly disappointing. Kikuchi induced poor contact, which is normally a good thing. But the results were unfavorable.

Expected Stats Looked Better

Considering the misleading nature of ERA, let’s use an expected stat to assess Kikuchi. These advanced metrics tell us what should’ve happened to batted balls based on exit velocity and launch angle. More importantly, they remove the influence of defense (good or bad) and the scorekeeper from the equation.

For example, the expected batting average (xAVG) of Bregman’s batted ball was .200 – Escobar’s was even lower (.020). Yet, the box score says both players hit a double that improved their AVG, OBP, SLG, and wOBA.

Okay, let’s compare Kikuchi’s wOBA to his expected weighted on-base average (xwOBA). Doing so may help us better understand his difficulties with RISP.

xwOBA Says Kikuchi Should've Done Better With RISP
wOBA
xwOBA
wOBA-xwOBA
Total
.295
.279
.016
No MOB
.251
.280
-.029
- 1B only
.322
.263
.059
- RISP
.377
.289
.088

As expected, Kikuchi’s wOBA with RISP was dreadful. But take a look at his xwOBA, which remained stable regardless of base runner situation.

The large positive delta between Kikuchi’s wOBA and xwOBA signals he didn’t fare as well as anticipated. In fact, his wOBA-xwOBA difference with RISP was one of the largest in the majors in 2020. Only Adrian Houser (.114) of the Brewers and Rick Porcello (.096) of the Mets were ahead of Kikuchi.

Note: Unless otherwise stated, comps refer to the 96 pitchers throwing 750-plus pitches as a starter in 2020.

Bad Luck?

Before discussing Kikuchi further, let’s quickly cover Statcast’s six categories of contact quality. Three favor hitters: Barrels, Solid Contact, and Flares/Burners. Pitchers prefer the others, which are types of poor contact: Weak, Under, and Topped.

Barrels are the most lethal batted balls. They generally have an exit velocity of at least 98-MPH and a launch angle between 26-30 degrees. The vast majority of home runs are barrels.

Solid contact just misses the launch angle/exit velocity range of barrels, but produces excellent results also. Just over 12-percent of homers hit in 2020 were off solid contact.

MLB Success in 2020 Based On Quality of Contact
Rate
HR
Avg EV
AVG
wOBA
Barrels
7.2%
1880
104.5
.797
1.373
Solid
6.0%
285
100.9
.472
.611
Flare/Burner
24.2%
2
93.1
.663
.616
Poor*
62.7%
132
82.6
.131
.126
* Includes Weak, Under, and Topped contact

The last favorable category for hitters – flares and burners – occurs when the hitter misses the launch angle or exit velocity necessary for barrels or solid contact. Nevertheless, hitters reach base at a high rate on flares/burners.

Statcast defines “weak” contact as balls with an exit velocity under 60-MPH. “Topped” balls typically lead to unproductive grounders. Balls hit “under” create fly balls with predominantly poor results, although 132 home runs fell into this category this year.

Now, let’s apply this knowledge to Kikuchi.

A review of opponents’ success with RISP when facing Kikuchi reveals his numbers resemble MLB norms with the exception of two types of poor contact – Under and Topped. The following compares his combined stats for these two categories to MLB averages.

Kikuchi v MLB On Poor Contact w/RISP*
Rate
EV
wOBA
xwOBA
wOBA-xwOBA
Kikuchi
72.4%
84.6
.323
.168
.155
MLB
62.7%
81.7
.121
.139
-.018
* Poor Under and Topped Contact only

Despite inducing significantly more poor contact than the MLB norm, Kikuchi’s wOBA was dramatically higher. Only Oakland’s Sean Manaea (.168) had a higher wOBA-xwOBA delta.

Kikuchi’s high .323 wOBA on poor contact feels like bad luck that would’ve normalized over a full season. For evidence, consider 2019. The highest wOBA with RISP among pitchers throwing 2,000-plus pitches last year was Jorge López (.227). And Kikuchi? He had a .165 wOBA.

I’m not suggesting Kikuchi’s uneven 2020 is simply a byproduct of misfortune. However, it’s reasonable to expect he would’ve enjoyed much more success on poor contact over the span of a normal 162-game season. Having said that, there is another factor worthy of scrutiny when he’s facing RISP – free passes.

He Didn’t Always Attack The Zone

Kikuchi’s 17-percent walk rate with RISP was fifth highest in the majors behind Cincinnati’s Sonny Gray (20.8), Pittsburgh’s J.T. Brubaker (20.5) and Chad Kuhl (17.1), and San Francisco’s Johnny Cueto (17.7). Since this is much higher than Kikuchi’s 10.3-percent walk rate for the season, I examined his willingness to throw strikes depending on baserunner situations.

The following provides the percentage of pitches Kikuchi threw within Statcast’s Game Day (GD) strike zone during the situations we’ve been discussing. It’s important to remember pitches within the GD strike zone are occasionally balls. Why? Umpiring, catcher framing, and ahem…umpiring.

Kikuchi's Strike Rate Based On MOB Situation
Total
No MOB
MOB
1B Only
RISP
51.2%
50.7%
51.9%
63.3%
43%

This year, 29 starters threw at least 50-percent of their total pitches within the GD zone – Kikuchi was one of them. So were fellow Mariners Marco Gonzales (53.7) and Justus Sheffield (50) and former teammate Taijuan Walker. Other notable names in this group: Clayton Kershaw, Yu Darvish, Julio Urías, Kyle Hendricks, Tyler Glasnow, Lance Lynn, Dinelson Lamet, Luis Castillo, and Lucas Giolito. All are good pitchers.

With a runner on first base only, Kikuchi seemed particularly aggressive. Only Urías (69.2-percent) threw strikes more often than Kikuchi did (63.3). With RISP, over half (17) of our group remained at at-or-above 50-percent. Conversely, Kikuchi’s 43-percent strike rate was the lowest.

Not every pitcher must throw a high percentage of their pitches in the zone to succeed. AL Cy Young Award winner Shane Bieber threw just 40.5-percent of his pitches within the GD zone, which ranked last in our original group of 96. Still, Kikuchi threw over half of his pitches in the strike zone in all situations except with RISP. Unless avoiding the strike zone was by design, this seems relevant.

Strike One Was Elusive

A potential area Kikuchi may need to address next season is throwing strike one. The first pitch to 49.5-percent of the 194 batters he faced this year was a ball. Among 133 starters facing at least 150 hitters, only rookies Cristian Javier (53.3) of Houston and Kris Bubic (52.0) of the Royals offered a 0-0 ball at a higher rate than Kikuchi. For context, Gonzales was best on the Mariners with 35-percent.

But there’s more.

It turns out Kikuchi threw a ball during 45.3-percent of all no-strike counts (0-0, 1-0, 2-0, 3-0), which was highest in the majors. Not a preferred result considering pitchers are generally more successful when ahead in the count.

% Of Hitters Seeing A First-Pitch Ball From Kikuchi
Count
Hitters
Balls
%
0-0
194
96
49.5
1-0
96
37
38.5
2-0
37
17
45.9
3-0
17
6
35.3
Total
344
156
45.3*
* Highest Among MLB Starters

Here’s a not-so-fun fact. Eight of the 20 walks Kikuchi issued this year happened with RISP – half of them on a 3-0 count with RISP. For the season, he surrendered six total walks on a 3-0 count. Yes, it’s a small sample size. However, losing a hitter on a 3-0 count six times in nine games seems excessive. It turns out it was. Last year, he allowed five walks on a 3-0 count in 32 starts.

Fastball Command Was Sketchy

Every pitcher throws “waste” pitches, offerings well outside the strike zone. Some pitchers produce multiple swings and misses on wasted pitches – not Kikuchi. He induced just one swing and miss from 69 wasted pitches.

The vast majority (68.1-percent) of Kikuchi’s wasted pitches fell into Statcast’s “fastball” category – the four-seam fastball, two-seam fastball, cut fastball, and sinker. That’s the highest rate among 123 starters throwing 50-plus waste pitches. This sketchy fastball command was apparent during the no-strike counts we just discussed.

Yusei Kikuchi’s wasted four-seamers on no-strike counts

It turns out 24.6-percent of Kikuchi’s wasted pitches were four-seamers thrown during no-strike counts. That’s the second highest rate recorded by any starter other than 22-year-old Cardinals rookie Johan Oviedo (33.3-percent). This seems suboptimal.

Austin Nola Seemed To Help

We know a catcher’s framing skills influence ball and strike calls. Moreover, their blocking ability factors into a pitcher’s willingness to throw pitches likely to break into the dirt, especially with a runner on third base. With this in mind, I wanted to see whether Kikuchi performed differently based on the receiver behind the plate.

It appears Kikuchi performed best with Austin Nola. The former LSU Tiger caught three of the lefty’s first five starts in 2020 before the Mariners traded him to the Padres in late August. Kikuchi’s walk and strikeout rates were noticeably better with Nola behind the plate compared to Seattle’s other three backstops this year – Luis Torrens, Joseph Odom, and Joe Hudson.

Kikuchi Results Based On Catcher
PA
K%
BB%
AVG
wOBA
xwOBA
Austin Nola
65
27.7
3.1
.254
.273
.258
Luis Torrens
66
22.7
10.6
.211
.284
.265
Joseph Odom
45
22.2
15.6
.211
.293
.307
Joe Hudson
18
22.2
22.2
.357
.414
.333

Still, Kikuchi’s xwOBA was good when Torrens was his battery-mate. With Odom, he was just below league-average, which isn’t bad. Hudson caught him just once, so let’s just set that outing aside.

Is it possible Kikuchi was more comfortable with Nola as his catcher? Sure, but it’s important that we don’t lose sight of the fact 2020 was a small nine-start sample. He was fine with Torrens with the exception of the change in walk and strikeout rates. Perhaps a full Spring Training of the duo working together elevates their success as a battery.

Finally

If Dipoto is serious about the Mariners contending next season, the team will need a consistently effective Yusei Kikuchi. After all, the team probably won’t acquire premium starting pitching this offseason. Moreover, expecting one of the organization’s talented young arms to step into such a crucial role, as a rookie, would be a bridge too far.

Assuming Kikuchi’s 2021 results more closely resemble his 2020 expected stats, he can elevate Seattle’s rotation. Imagine an effective and productive top-3 consisting of Gonzales, Sheffield, and Kikuchi. They would be a formidable match for AL West rivals.

Kikuchi has the talent to make such a scenario reality. Better success on poor contact is inevitable. However, he’ll need to throw more first-pitch strikes, improve his fastball command, and remain aggressive in the strike zone with RISP. All he has to do is execute – easier said than done.

If Kikuchi improves on these elements, the Mariners’ decision on his contract becomes far more complex. Dipoto would probably say he’d prefer that kind of tough call. Then again, another season of inconsistency from the enigmatic southpaw makes the team’s choice a no-brainer.

My Oh My…

Got a take on what you just read? Talk about it here!

Image courtesy of Stephen Brashear | AP Images
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Luke Arkins

Luke is a native New Yorker, who grew up as a Mets fan. After the US Navy moved him to the Pacific Northwest in 2009, he decided to make Seattle his home. In 2014, Luke joined the Prospect Insider team. During baseball season, he can often be found observing the local team at T-Mobile Park. You can follow Luke on Twitter @luke_arkins