Will Edwin Diaz Regress in 2023?
Plus thoughts on his 5-year, $102 million deal with the Mets
Of course he will.
The man literally struck out over half the batters he faced in 2022 while recording the third lowest FIP (0.90) among relievers who ever pitched at least 60 innings in a single season.
Diaz is very, very likely going to regress in 2023. The question is by how much, and should we view his new contract as a wise move by his employer?
In order to answer these questions, I want to highlight just how spectacular Diaz was this year while saving 32 games for the 101-win Mets. This tweet should help:
Not only was Diaz dominant when compared to his 2022 peers, but he had a historic season when looking at all relievers in recent history. As mentioned, his 0.90 FIP was the third lowest mark ever (min. 60 IP). His 50.2 K% was tied for the highest rate ever. His 42.6 K-BB% was the third highest ever, behind just two Craig Kimbrel seasons. And finally, Diaz’s 24.7 swinging strike rate was the second highest ever (behind 2004 Brad Lidge, neat!).
We’re focusing on these metrics over saves and ERA since they better reflect a relief pitcher’s true skill level, but that doesn’t mean there can’t be year-to-year variation in performance, especially when a reliever (whose season is defined by a small sample size) is coming off such an outlier campaign.
To better illustrate this, I took the 10 best seasons by FIP and looked up what those pitchers did the following year. I expected regression and that’s what we got:
This isn’t to say that any of these relievers were “frauds” — it’s just to point out that repeating historical greatness is really, really hard.
There are examples of it, though. You’ll see in the chart above that 2016 Kenley Jansen actually improved on his historically low FIP the following year. Among the other all-time single-season FIP leaders, 2011 Kimbrel is 13th (and his follow-up 2012 season has the record). “Rob Dibble” actually has 4 of the top 30 FIP seasons for his 1989-1992 run with the Reds.
And yet, there’s a whole lotta red in the image above. Most of the RPs who posted a historic FIP were still good the following year. They just weren’t historic, which brings us to the contract.
As of now, here are the details we know about Diaz’s deal:
Base is 5 years, $102 million
It comes with an opt-out after 2025, a $20 million option for a 6th season, and a $12 million signing bonus.
$26.5 million is deferred, which lowers the Mets’ Competitive Balance Tax number.
For reference:
The deferred payments definitely help from a team-building standpoint. They lower the average annual value (AAV) of the deal, which will allow for owner Steve Cohen to sign off on more high-profile moves this winter. Don’t forget, the Mets have more key free agents — Jacob deGrom, Brandon Nimmo, and Taijuan Walker included. Those are just their own. Then there’s the question of what the front office needs to add to last year’s team to get over the hump.
Max Scherzer is entering his age-38 season while deGrom turns 35 in June. This is a veteran, win-now roster. It’s why the 2022 letdown was so gut-wrenching for fans. Cohen is going to keep the Mets in the mix in a way the previous ownership never did or could, but they also aren’t the Dodgers. More work is needed on the minor league player development side, though the organization has a few key prospects (Francisco Alvarez, Brett Baty, etc.) coming through the pipeline next year.
Mostly, though, it’s a core built to win in the present, and preferably in a hurry. That’s why Diaz is coming back on a deal that rival front offices probably never would’ve considered.
And that notion right there is where most of the analysis for Diaz’s contract starts and ends. It’s unlikely that he ever repeats his 2022 apex. He was just that good and had a favorable/”lucky” left on base rate (relative to both his career and the league as a whole).
Is it possible he has another borderline historic season in the coming years? History tells us that yes, it’s very possible. Though FIP is a better stat to use than ERA, it still isn’t the perfect year-over-year metric. When looking at the top 24 single-season strikeout rates, for instance, there are only 14 unique names. Several relievers were able to replicate a historically superb K% multiple times.
Thanks to what we know about Stuff+/Location+/Pitching+ from The Athletic’s Eno Sarris, “stuff” is more predictive year over year than locations. And thus, betting on a pitcher’s “stuff” (in Diaz’s case this correlates to SwStr%, K%), is a worthwhile bet. Diaz posted multiple stats that were all-time worthy in 2022. It wasn’t just the FIP (which, lol — Diaz was incredible this year).
To tie a bow on this, I don’t love the contract and will bet against anyone who thinks Diaz will ever again be as good or better than he was in 2022. 5 years is an eternity for a closer, but if the Mets win it all with Diaz as a contributor then it simply won’t matter. And for fantasy, he’s still one of the first relievers off every draft board next spring (Tier 1 closers Clase and Diaz. That’s it, right?). His command might waver at times throughout this contract, but in the short term it’s reasonable to project a 40% strikeout rate, which is both absurd and hilarious.
And lastly, it’s yet another sign that these are the new Mets. Cohen’s Mets. Just in case you didn’t get the message from Francisco’s Lindor $341 million extension or via Scherzer’s $43 million AAV last winter, this is an owner who wants to win, and who literally puts his money where his mouth is. We shouldn’t be surprised by anyone this team brings in for next season, nor by the cost. Diaz was an overpay. It’s also only Step 1 of the Mets’ offseason.