Top Notes From the Seattle Mariners ZiPS Projections for 2024

Dan Szymborski of FanGraphs has released his ZiPS projections for the upcoming season. How do the 2024 Seattle Mariners stack up?

SEATTLE, WASHINGTON - JULY 27: Julio Rodriguez #44 of the Seattle Mariners blows a bubblegum bubble during the fourth inning against the Texas Rangers at T-Mobile Park on July 27, 2022 in Seattle, Washington. (Photo by Alika Jenner/Getty Images)

After ending a two-decades-long playoff drought in 2022, the Seattle Mariners expected to build on their taste of success in 2023. And while they came close, finishing within two games of the AL West title and one game behind the Toronto Blue Jays for the final AL Wild Card spot, consecutive postseason berths for the first time since 2000 and 2001 remained elusive for the M’s.

However, their failure to repeat as playoff contenders in 2023 was not due to their overall performance, at least according to one set of metrics.

The Mariners won 88 games last season, which is exactly how many they should’ve won, according to Dan Szymborski’s 2023 preseason ZiPS projections at FanGraphs. The famous model, which uses large aggregates of weighted data to project future performance, pegged Seattle as an 85 to 90-win team heading into the year. That should give you a sense of ZiPS’ accuracy and why it’s so respected across baseball.

In terms of individual Mariners players, though, ZiPS’ projections varied more widely last season. For example, the system underestimated the value of many of Seattle’s top players, like superstar Julio Rodríguez (5.0 projected fWAR versus 5.9 actual fWAR), shortstop J.P. Crawford (2.8 projected fWAR versus 4.9 actual fWAR) and catcher Cal Raleigh (2.4 projected fWAR versus 4.7 actual fWAR.)

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Conversely, ZiPS greatly overestimated first baseman Ty France’s value (3.2 projected fWAR versus 0.5 actual fWAR), which demonstrates that despite the model’s accuracy in the aggregate, it can misfire on individual player projections. That said, ZiPS remains a trusted indicator of future success.

Here is what we can learn from the model’s projections for the 2024 Seattle Mariners.

Position Players

Some key takeaways:

  • These projections do not account for the addition of catcher/DH Mitch Garver, whom the Mariners signed to a two-year, $24 million contract in December 2023. Garver’s projected 1.6 fWAR (per the Steamer projection system) could largely make up for the departure of Teoscar Hernández (1.8 fWAR in 2023) who signed with the Los Angeles Dodgers in early January.
  • The ZiPS projections were also published before the trade that sent infielder Jose Caballero (2.2 fWAR in 2023) to the Tampa Bay Rays for outfielder Luke Raley (2.6 fWAR in 2023). The Mariners will add Raley’s pop from the left side while dealing from a position of strength in the middle infield; earlier this offseason, they acquired infielder Luis Urías from the Boston Red Sox. Raley effectively replaces Jarred Kelenic (now with the Atlanta Braves) on Seattle’s roster.
  • In another trade this winter, the Mariners acquired Mitch Haniger from the San Francisco Giants. Haniger posted a negative fWAR in San Francisco last season, but that was mostly due to injury. He projects to finish with 1.0 fWAR in 2024, which would represent a slight downgrade from Eugenio Suárez’s right-handed power bat; the third baseman projects for 2.0 fWAR in 2024 with the Arizona Diamondbacks.
  • Overall, ZiPS appears to be correct in its analysis of the 2024 Mariners’ projected lineup. The top half of the unit looks sturdy, with Rodríguez, Crawford, France and Raleigh leading the way. However, the other moves Seattle has made this offseason have only helped the club break even – they don’t look like clear and obvious upgrades. Considering the Mariners weren’t good enough to make the playoffs in 2023, the lineup still has to be somewhat of a concern.

Starting Pitching

This is where the Mariners are strongest, as you may recall from last season. Health permitting, their rotation is easily a top-five group in the entire sport, and ZiPS agrees. The fact that this is still true even after the team dealt left-hander Robbie Ray to the Giants is a testament to this group’s depth and upside.

The Mariners’ vaunted staff will once again be led by ace Luis Castillo, who will be followed in some order by Logan Gilbert and George Kirby, with Bryan Woo, Bryce Miller, and Emerson Hancock also in the mix. Anthony DeSclafani will likely factor in as depth, too.

A few notes about this staff:

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  • ZiPS sees Castillo as a frontline starter once again, projecting a 4.0 fWAR/126 ERA+ in 2024 after forecasting a similar 4.2 fWAR/133 ERA+ ahead of the 2023 campaign. Castillo finished last season with 3.4 fWAR, however, meaning he slightly underachieved. We’re not going to blame Seattle’s failure on Castillo, though.
  • Woo and Miller will likely compete for a big league starting spot in 2024. The two young hurlers profile similarly as fastball-dominant right-handers, but the competition will come down to health and performance. Assuming the former, ZiPS favors Miller (projected 2.3 fWAR/106 ERA+) over Woo (projected 1.6 fWAR/100 ERA+) to initially win a spot in the Mariners’ rotation.
  • Perhaps Woo can win a place in the rotation anyway because ZiPS is not especially high on rookie right-hander Hancock (projected 0.9 fWAR/93 ERA+ in 2024) or veteran DeSclafani (0.9 fWAR/91 ERA+ in 2024). Fortunately, the Mariners have options. An embarrassment of pitching riches, if you will.

Relief Pitching

The strength of Seattle’s pitching staff isn’t just limited to the team’s starters; it extends into the bullpen, too.

Jerry Dipoto made a head-scratching decision to deal closer Paul Sewald to the Diamondbacks last season after trading setup man Erik Swanson to the Blue Jays the winter before. And yet? Seattle’s bullpen still performed quite well in 2023, meaning we should trust that Dipoto has the unit in a good place for 2024 as well.

ZiPS is high on the Mariners’ top two relievers Andrés Muñoz (1.3 fWAR/142 ERA+) and Matt Brash (1.3 fWAR/116 ERA+), giving Seattle a solid foundation to work with. The rest of the bullpen projects to be solid but unspectacular, with a gamut of arms including Gabe Speier, Prelander Berroa, Jackson Kowar, Casey Sadler, Tayler Saucedo, Trent Thornton, Justin Topa and Eduard Bazardo, along with recent addition Austin Voth (projects for 0.2 fWAR/85 ERA+).

Bullpens are typically the most difficult position group to project due to their seasonal variance. Fortunately for the Mariners, though, ZiPS projects a collective bullpen fWAR of 3.6. That means manager Scott Servais should be able to leverage a deep and talented relief corps once again in 2024.

Closing Thoughts

When the Mariners ZiPS projections were published in mid-December, Dan Szymborski had them finishing with somewhere between 85 and 90 wins, just as he did going into 2023.

This projection seems accurate given that the Mariners have not truly upgraded their lineup from last season, and they are bringing back many of the same pieces from 2023’s pitching staff, both in the starting rotation and the bullpen.

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The real question, though, is whether 85-90 wins is good enough to contend in the American League. Remember that Seattle’s primary division rivals, the Texas Rangers and Houston Astros, reign as the most recent World Series champions.

Given how close many of the AL playoff races were last year, the Mariners should find themselves in the conversation in 2024. But how far they’ll go hinges on the core that’s already in place.