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Once again, elite starting pitching has taken center stage during the MLB playoffs. A not-so-subtle reminder that assembling a postseason rotation is the greatest challenging facing the Seattle Mariners and GM Jerry Dipoto.

Just how important is a starting rotation to perennial postseason contention? The three clubs reaching the playoffs in each of the last three seasons (Dodgers, Astros, and Yankees) all had at least four above-average starters on their respective staffs every year.

To clarify, our definition of an above average starter is a pitcher facing at 400-plus hitters with an expected weighted on-base average (xwOBA) better than the league-average.

Rotations Drive Postseason Leaders
WSNHOUNYY
Max ScherzerGerrit ColeJames Paxton
Stephen StrasburgJustin VerlanderC.C. Sabathia
Patrick CorbinZack GreinkeMasahiro Tanaka
Aníbal SánchezWade MileyDomingo Germán

Realistically, the Yankees’ staff doesn’t share the same rarefied air as the Dodgers, Astros, and the NL champion Nationals. Perhaps that’s why Houston has pushed the Bombers to the brink of elimination in the ALCS.

Still, recent Yankees rotations certainly deserve credit for helping the club achieve something Mariners fans haven’t witnessed in two decades – multiple postseason appearances by the home team within a five-year span.

Ouch.

It’s not just the current postseason stalwarts relying on their rotations. Every World Series participant since 2015 has boasted four-plus above-average starters. The same applies to the final three teams still playing in this year’s postseason.

What About The M’s?

So, how have Mariners rotations performed during the five-year period we’re discussing? Not nearly as good as the teams already mentioned and many others.

Above Average SEA SP’s Since 2015
2015Félix HernándezHisashi IwakumaTaijuan Walker
2016James PaxtonTaijuan Walker
2017James Paxton
2018James PaxtonMarco GonzalesWade LeBlanc
2019Marco Gonzales

With the exception of Marco Gonzales, the pitchers listed above are no longer with the Mariners or not expected to be with the team next year.

Seattle’s rotation flirted with hitting rock bottom this year. Here’s where the starting staff stood using an array of old school and advanced metrics.

M’s Rotation Ranked In Bottom-Third Of MLB
SEA
Rank
xwOBA
.341
25
ERA
5.21
21
FIP
5.12
26
HR%
4.3
22
SO%
17.5
30
BB%
6.6
2
AVG
.281
29
OBP
.334
23
SLG
.501
28
WHIP
1.43
23

Mariner starters collectively delivered results similar to the staffs of the Orioles, Tigers, Royals, and the mile-high Rockies in 2019. Clearly, Dipoto and his staff have a lot of work to do to build a rotation capable of sustaining a perennial postseason contender.

To be fair, the Mariners are retooling, so it’s not surprising the club lagged well behind most of the league in 2019. Then again, a review of the organization’s stable of current and potential future starters suggests promise, but little certainty.

Marco Gonzales

Gonzales was clearly Seattle’s best pitcher this year. The team’s Opening Day starter made a career-high 34 starts joining Félix Hernández, Jason Vargas, and Hisashi Iwakuma as the only Mariners with a 200-plus inning season in the last decade.

Still, it’s important we keep Gonzales’ contributions in perspective. In September, a recurring on-air narrative suggested improvement over his 2018 production. Yet, the 2019 stat-line of the Gonzaga Bulldog wasn’t meaningfully better than the year prior.

The following illustrates Gonzales’ 2018 and 2019 numbers, plus this year’s MLB average for each category.

Marco’s 2018 v 2019
2018
2019
MLB
xwOBA
.313
.312
.318
ERA
4.00
3.99
4.54
FIP
3.43
4.15
4.51
AVG
.267
.264
.256
OBP
.307
.314
.320
SLG
.414
.422
.444
SO%
21.1
17.0
22.3
BB%
4.7
6.5
7.7
HR/9
0.9
1.0
1.4
WHIP
1.22
1.31
1.32

Overall, Gonzales was slightly above average in most categories, but his 2019 numbers didn’t appreciably improve compared to the previous season. The southpaw’s strikeout rate was significantly lower than the norm, but he proved stingy when it came to surrendering walks and home runs.

To be clear, I’m not dismissing Gonzales’ excellent season or downplaying his value to the Mariners. However, a pitcher with his numbers can’t be the marquee attraction of a contender’s rotation.

To see what I mean, here are the top five rotations in MLB (based on xwOBA) followed by the AL postseason clubs not in the top-five.

Where do you place Marco in these rotations?
HOUColeVerlanderGreinkeMiley
LADMaedaBuehlerKershawRyu
TBRSnellMortonGlasnow
NYMdeGromSyndergaardWheelerStroman
WSNScherzerStrasburgCorbinSánchez
MINOdorizziBerriosPérez
NYYPaxtonTanakaSeverinoGermán
OAKManaeaBassitt

If Seattle’s end-goal is to build a powerhouse, let’s assume management strives to have a better rotation than Oakland’s staff. With that in mind, Gonzales’ stats aren’t significantly better than any other team’s third best starter.

It’s worth noting the Rays also had former Mariners farmhand Ryan Yarbrough and 25-year-old Yonny Chirinos on their staff; the pair alternated between starting and relieving. Yarbrough had a better xwOBA (.297) than Gonzales did, while Chirinos’ (.317) was similar to Seattle’s top starter.

And about those A’s. It’d be unfair to move on without acknowledging Oakland has two top-shelf pitching prospects projected to help buoy the club’s rotation starting next year – A.J. Puk and Jesus Luzardo.

Bottom line: When the 2019-version of Marco Gonzales is the Mariners’ third or fourth best starter, Seattle fans should free up space on their October calendar for postseason action in the Emerald City.

Next up, an international free agent who struggled during his rookie campaign.

Yusei Kikuchi

Kikuchi’s stat-line was considerably less impressive than fellow crafty-lefty Gonzales. In fact, the Japanese import ranked near the bottom of baseball in most categories.

Kikuchi
MLB
Rnk**
xwOBA
.341
.318
84
ERA
5.46
4.54
93
FIP
5.71
4.51
97
AVG
.295
.256
95
OBP
.348
.320
91
SLG
.539
.444
98
SO%
16.1
22.3
91
BB%
6.9
7.7
56
HR/9
2.0
1.4
98
WHIP
1.52
1.32
94
** Rank among 98 SPs with facing 500+ hitters

There were glimpses of what Kikuchi could provide to the Mariners – an August complete-game shutout, 11 outings of six-plus innings, including three lasting seven or more frames. But inconsistency and home runs plagued his first year in the Emerald City.

There were nine occasions when Kikuchi didn’t reach the fifth inning. Moreover, he surrendered multiple home runs in 12 starts, second most in MLB behind Trevor Bauer and former teammate Mike Leake. Bauer and Leake achieved the dubious feat 13 times, although both logged over 30 more innings than Kikuchi did this year.

Kikuchi likely remains with the Mariners through 2022 at the very least. After the 2021 campaign, there’s a player option for one more season or Seattle can exercise a four-year club option keeping him with the club through 2025.

Kikuchi’s place in the 2020 rotation is secure, although he’ll be looking to demonstrate significant improvement and more consistency. Otherwise, it’s unlikely he evolves into the number-two starter Dipoto envisioned the 28-year-old could be.

Farm Aid

Mariners manager Scott Servais didn’t have much to work with this season. However, the organization’s minor-league system has several intriguing prospects in the pipeline.

Justus Sheffield

Sheffield’s first season as a Mariner included a reassignment from Class-AAA Tacoma to Class-AA Arkansas, a potentially humbling experience for a former top-100 prospect.

During his September call-up, Sheffield encountered some difficulties. But he did flash the talent that prompted the Indians to select him in the first round of the 2014 draft. We recently suggested the 23-year-old might only need time to prove himself.

Barring unforeseen circumstances, Sheffield begins 2020 in the Mariners’ rotation since there’s nothing left to prove in the minors. Perhaps the southpaw’s performance will justify Dipoto’s decision to deal former ace James Paxton to land the Tennessean.

Justin Dunn

Greg Johns of MLB.com notes Dunn is one of several prospects (including Sheffield) the Mariners expect to be “integral parts of next year’s plans.” MLB Prospect Watch considers him a Top-100 prospect. Similarly, our most recent rankings rate the righty as fourth best in Seattle’s system. That said, his long-term role with the club is far from certain.

Prospect Insider founder Jason A. Churchill suggests Dunn must eventually demonstrate a better changeup and improved fastball command to stick as a starter. Still, there’s time for him to evolve with the Boston College product likely beginning 2020 with Tacoma.

Even if Dunn doesn’t remain a starter, he potentially delivers value as a high-leverage reliever.

Logan Gilbert

The 22-year-old is rising fast through the minor-league ranks and could develop into a top-of-the-rotation option. If Gilbert continues his ascent at his current pace, the Stetson alum may see action with Seattle as early as next year.

Perhaps Gilbert follows in the footsteps of the two most prominent major leaguers from his alma mater – Cy Young Award winners Jacob deGrom and Corey Kluber.

George Kirby

Kirby is another quick riser in our rankings and perhaps the Mariners’ system. The right-hander was the club’s first round pick this year and already impressing evaluators with Churchill suggesting he’s a potential number-two starter.

It’s plausible Kirby takes the same fast track as Gilbert next season. If that’s the case, the Elon alum could make his presence felt by 2021.

Ricardo Sanchez

Sanchez doesn’t possess the upside of the youngsters already discussed. However, the left-hander does have a full season of AA under his belt and he’s already on the 40-man roster. The Venezuelan potentially develops into a back-end starter.

The Next Wave

There are others, who may eventually have some level of impact with the Mariners.

This year’s second round pick, Isaiah Campbell, who the organization optioned to rest after an arduous senior year with Arkansas. Another second rounder, Sam Carlson, appears on track after missing two seasons due to Tommy John surgery. The 20-year-old should return to action next spring.

Several other hurlers under 21-years-old may eventually make their presence known – Juan Then, Damon Casetta-Stubbs, and Ljay Newsome. For now though, they’re just names appearing in the bottom-half of most prospect rankings.

I Know A Guy

Every World Series winner since 2015 has went outside the organization to get a headliner for its rotation. I refer to these kind of starters as “guys” – pitchers capable of taking a club to the next level.

“Guys” Recent World Series Champs Acquired
2019 AstrosGerrit Cole (Offseason Trade)
2019 YankeesJames Paxton (Offseason Trade)
2019 NationalsPatrick Corbin (Free Agent)
2018 Red SoxChris Sale (Offseason Trade)
2017 AstrosJustin Verlander (Deadline Deal)
2016 CubsJon Lester (Free Agent)
2015 RoyalsJohnny Cueto (Deadline Deal)

We don’t know which team wins the 2019 Fall Classic, but the three finalists have added a “guy” in recent years. The Yankees got Paxton from Seattle last offseason, while Patrick Corbin was a free agent addition by the Nats. Gerrit Cole joined Houston via trade in January 2018.

Just four months prior to adding Cole, the Astros acquired Justin Verlander in an eleventh hour deal on August 31. Similarly, the 2015 Royals snagged Johnny Cueto at the trade deadline.

Boston acquired Chris Sale by shipping multiple prospects several years ago. Sale’s presence was vital to the Sawx earning the 2018 World Series trophy.

Prior to the 2015 season, the Cubs signed Jon Lester to a long-term contract. The Tacoma, Washington native helped propel the North Siders to multiple postseason appearances and a historic title in 2016.

Could The M’s Be Different?

Although the names we’ve discussed should provide hope for Mariners fans, I think it’s worth repeating something a two-star Army General once told me:

“Hope is not a course of action.”

Sure, it’s possible everything goes well for Seattle. Perhaps, Kikuchi and Sheffield blossom into what the team hopes they can be. Maybe Dunn remains a starter and Gilbert becomes third great pitcher hailing from Stetson. Then again, hope is not a course of action.

In the end, Dipoto likely turns to the trade market or free agency to get rotation help. Maybe it’ll be to acquire the Mariners’ “guy.”

Moving Forward

Watching this year’s postseason unfold reinforces the notion a robust starting rotation is vital to serious postseason contenders. The Mariners are heading in the right direction, but must achieve the similar level of excellence currently demonstrated by the Nationals, Astros, Dodgers, and Yankees.

Sure, having a top-shelf rotation doesn’t guarantee success; just ask Mets fans about that. Still, Dipoto and crew are doing a nice job of acquiring and developing prospects. If they can construct a superior starting staff either organically and/or by using outside resources, Seattle becomes a regular World Series contender.

Considering Mariners fans are currently enduring an 18-year postseason drought, they deserve to experience October glory on a regular basis.

Wouldn’t you agree?

My Oh My…

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