Andres Muñoz Is a Tier 1 Reliever. Period.
In saves plus holds fantasy leagues Muñoz should be drafted among the elites.
I’m a fan of fantasy baseball leagues that use saves plus holds. Don’t get me wrong - I love the history of traditional 5x5 roto leagues. I’m a baseball fan, which means I have an old soul. I’ll always support the idea that 5x5 with batting average, wins, and saves is the “purest” form of fantasy baseball.
But saves plus holds is more fun. Sorry if this offends.
Maybe I shouldn’t have opened with my thoughts on saves-only leagues. This is going to get misconstrued as me bashing them. But I never said that! I still play in one, even. I just prefer saves plus holds because the focus is more on player talent than which innings a manager chooses to use his relievers in.
We’ll circle back to that. Let’s first talk about Andres Muñoz, Seattle’s flame-throwing right-hander fresh off his age-23 season in which he was a top-5 finisher among MLB relievers in a crazy number of important metrics:
2nd in K-BB%
4th in K%
3rd in xFIP
8th in WHIP
2nd in SwStr%
He also had a very helpful 52.6% ground ball rate.
Those ranks include the beginning of his season, when he was still discovering who he is as a pitcher. He got off to a hot start in April, but struggled badly in May with a poor 12.5 K-BB%, .389 batting average against, and a 5.75 FIP in 8 1/3 frames (we’ll get to why in a minute).
Then from June 13th through the end of the season he did this:
Using his full season stats, Muñoz’s 2022 SwStr% was the 5th highest single-season mark of all time among relievers who tossed at least 60 innings (sandwiched between Eric Gagne’s 3 elite years from 2002-04!).
If we only looked at his SwStr% from June 13th on — which didn’t hit the 60 IP threshold but bear with me — it would’ve been the 3rd highest mark ever, only trailing 2004 Brad Lidge and 2022 Edwin Diaz.
So what changed?
Well, Muñoz throws hard — really hard — but his fastball isn’t actually his best pitch. His slider is, and the Mariners worked with their burgeoning relief ace to throw it more early in the year.
In April, he was slider-focused, and the results were great. Then in May he started falling in love with the heater again, and well, his results suffered. The above graphic displays his fastball and slider usages throughout the year. The area where the four-seamer usage rose, and he threw it more than his slider, is where the struggles happened.
By the middle of June Muñoz recommitted to his slider and the rest is history.
So what makes his slider so special?
While his fastball isn’t “as good” as his slider, he still throws it 100.2 mph, the 2nd hardest pitch in baseball last season. As we learned with Hunter Greene’s rookie year, batters will eventually square up 100 mph four-seamers if they’re flat. This is why Muñoz runs into trouble when he prioritizes the heater.
But if he’s slider heavy? Imagine sitting on that and then getting the four-seamer up at the letters. Being slider-centric helps his fastball play up.
Meanwhile, while throwing it 65% of the time, Muñoz had the 4th best run value of any slider last season, according to Statcast. Minimum 100 plate appearances, Muñoz’s slider had the 5th best batting average against, the 3rd lowest SLG, and the 5th highest whiff rate. This is why the Mariners want him emphasizing it.
Wrapping Up
So yeah, in real baseball terms, Muñoz is a Tier 1 reliever. And in saves plus holds fantasy leagues he’s a stud. It’s a shame that those in saves-only formats won’t be able to enjoy his greatness as much as the rest of us.
Alright, that’s enough jokes about saves-only leagues. The truth is that I don’t hate Muñoz as a late-round option in those formats. The Athletic’s Corey Brock recently noted chances are Muñoz leads the Mariners in saves in 2023, but that they’ll continue to mix and match.
I read this as a situation where Muñoz could finish with 15-18 saves and Paul Sewald totals 12-15. In keeper leagues, even saves-only ones, Muñoz is an even more tempting pick as his career trajectory should lead to him accumulating more and more of Seattle’s save opportunities in the coming years. He just turned 24.
Lastly, there were beginning to be some concerns about Muñoz’s offseason foot surgery, but we got good news this week:
Here’s to a healthy (and dominant) campaign for what will likely be the final year of baseball’s “best kept secret.”