2024 Stuff+ Update Notes: Part 1 (Starting Rotation)
Yesterday, Eno Sarris and Jordan Rosenblum announced updates to their 2024 Stuff+ model that included multiple refinements, including:
Re-training the model on 2023 pitch data (allowing for the model to more accurately account for anomalies)
Adjustments for air density and altitude’s impact on pitch characteristics
Platoon split adjustments for individual pitches
i.e. the usability of a pitch when throwing to both right- and left-handed batters
For a more detailed breakdown of the exact adjustments made for 2024 Stuff+, read Eno’s awesome write-up (including his 2024 Fantasy SP Rankings) and give both Eno & Jordan a follow on Twitter (linked above).
However, if you (like me) are more focused on what these changes mean for the Cincinnati Reds’ pitchers, specifically. Keep on reading below!
Today’s focus? The Reds’ starting rotation.
Hunter Greene
Change of Note: 127 4SFB Stuff+ -> 120.1 4SFB Stuff+
Greene wasn’t impacted a ton by the latest Stuff+ update. His Aggregate Stuff+ moved from 124 to 119, but those numbers themselves are still elite and among some of the best SPs in baseball. The most important factor to monitor, though, is his 4SFB Stuff+. Greene’s 4SFB is his bread-and-butter and calling card, but the results on it were poor last year. When you look at the movement profile on the pitch too, there seems to be a lot of “noise” in the pitch (lack of repeatability).
While the pitch still grades above average, you would think a pitcher with Greene’s velocity would grade out closer to the Spencer Strider tier (138 Stuff+). Hopefully, this is an area of focus for Greene in 2024.
Greene (L) vs. Spencer Strider (R); notice how much variance Greene has in his horizontal movement
Nick Lodolo
Change of Note: 97 Aggregate Stuff+ -> 115.6 Aggregate Stuff+
Wow. Nick Lodolo had the 4th largest boost in Aggregate Stuff+ among all starting pitchers in this latest update. A lot of this change is due to just how unique Lodolo’s release points & movement profiles are compared to the rest of baseball. This latest Stuff+ run was trained using 2023 data, so Lodolo’s unique pitch types were able to be “trained against themselves.”
Something to monitor with Lodolo though: despite the boost in Stuff+, his Location+ has been sub-100 for two consecutive seasons now (below Major League average). Even if this Stuff+ spike is sticky, Lodolo will still need to display at least league average command to be successful.
Graham Ashcraft
Change of Note: 127.9 Aggregate Stuff+ -> 109.1 Aggregate Stuff+
Well, you win some and you lose some. Unlike Lodolo who saw one of the largest Stuff+ boosts in this latest run, Ashcraft saw the single largest drop in Aggregate Stuff+ among starting pitchers. Not ideal.
The majority of this drop is driven by an update in the current Stuff+ calculation to account for a pitcher’s ability to pitch to both right- and left-handed batters. While Ashcraft’s Slider grade dipped, it still grades out extremely well (166 -> 133 Stuff+) but his Cutter saw a significant drop too (116 -> 103).
All in all, a 109.1 Aggregate Stuff+ grade is still among some of the best pitchers in baseball. However, Ashcraft is no longer sitting among the elite-of-the-elite like he was at the end of last year (which, frankly feels more accurate).
Andrew Abbott
Change of Note: A Sweeper! With a 117.5 Stuff+ & 108.5 Location+
Another significant change that was added in the 2024 Stuff+ update was the ability for the model to differentiate between a pitcher’s Slider and Sweeper — and grade the pitch accordingly (for folks unfamiliar with a Sweeper, here’s a breakdown).
When Abbott’s Slider was re-classified, both the Stuff+ and Location+ grades improved (previously at 106 & 107, respectively). This change more accurately reflects the great results Abbott saw with the pitch in 2023 and also should be viewed as a sign of encouragement for anyone who may have had a doubt about Abbott having a true “out pitch.” The ability to locate a Sweeper with that much precision (108.5 is one of the best ST Loc+ grades in baseball) is an extremely valuable skill to own.
Frankie Montas
Change of Note: 84.6 Aggregate Stuff+ -> 96.1 Aggregate Stuff+
Montas only threw 26 pitches in all of 2023 after recovering from a major shoulder injury and, while it’s obviously a bit of a small sample size, the initial Stuff+ results from those pitches had me concerned. However, after the latest Stuff+ re-run, it appears the core parts of Montas’ arsenal are ready to rock.
Montas posted a 138 Stuff+ on a Slider that he threw only once, solid Location+ grades on his Sinker & Cutter, and threw his Splitter 8 separate times. The only real point of concern with Montas’ small sample is that his 4SFB graded pretty poorly, however he’s shown the ability to pitch very effectively as a SNK/SPL/SL/CUT pitcher in the past. Conveniently, this pitch mix also profiles better as a fit in Great American Ballpark too.
All in all, with a full offseason of good health behind him, I’m coming into 2024 optimistic about Frankie Montas.
Brandon Williamson
Change of Note: A Sweeper! With a 142.3 Stuff+ / 102 Loc+ & a Slider with a 142.9 Stuff+ / 110.3 Loc+
I found Brandon Williamson’s Stuff+ re-run to be very fascinating. In total, Williamson’s Aggregate Stuff+ number didn’t move a ton, but his underlying individual pitches showed a lot of promise. While his 4SFB still continues to grade extremely poorly (60.2 Stuff+, one of the worst often-used 4SFBs in baseball), Williamson’s Sweeper, Slider & Changeup (117.9 Stuff+) all graded as very solid pitches.
So what does this mean for Williamson in 2024? Likely (hopefully), that we will see Williamson start to pitch “backwards” more. The ability to command a distinct Slider & Sweeper should help Williamson attack both right- and left-handed batters, and his solid Changeup should help keep hitters honest as well.
In the latest re-run, Williamson’s Cutter did drop a bit in grade (107 -> 95.8). However, he was still able to locate the pitch well (100.7 Loc+), so the answer may also be relying on the CUT as a primary fastball more often too.
Nick Martinez
Change of Note: 92.1 Aggregate Stuff+ -> 102 Aggregate Stuff+
One of the recurring themes I seemed to notice with Stuff+ while doing the Stuff+ Notes in 2023 was a bit of a blind spot for Changeups. The latest Stuff+ re-run seemed to address that area as well.
After this run, Nick Martinez saw a pretty significant Stuff+ boost in his Changeup (97 Stuff+ -> 110) in addition to a boost in Stuff on his Curveball as well (86 -> 113). With his CH being his most oft-used pitch in 2023 (and his Curve ranking 3rd), these two changes gave Martinez a solid boost in Aggregate Stuff+.
One thing to note is that Martinez’s primary fastballs still are not grading above average. However, with a Curve & CH that he can rely on (and that he’s shown he can use to get ahead of hitters), I’m heading into 2024 optimistic about Martinez as well.
Thanks for reading!
Stay tuned for my breakdowns on the Stuff+ update’s impacts on Relievers & Prospects soon!
