The 2025 Free Agent Class Earned 10.4% More Than We Thought

Kim Klement Neitzel-Imagn Images

Last week, Ben Clemens wrote a fantastic piece comparing how well he, the FanGraphs crowd, and a set of other baseball websites and analysts did at predicting the fates of 2025 MLB free agents. His conclusion is that we, the crowd, did an overall great job. I concur. Yay, us!

Unaware that Ben had a piece in the works, I also spent time over the past few weeks testing the wisdom of the FanGraphs crowd against what free agents actually received this offseason, and hoped to publish my work in the newly revived Community Blog. After Ben’s article was published, the editorial staff at FanGraphs noted that I took slightly different slices of the data and conducted different analyses. They encouraged me to refine and update some of my analysis so they could then run it as a companion piece.

“Wisdom of the crowd” is the idea that the collective opinion of a diverse, independent group of individuals will come to a better decision than that of even the most well-informed individual expert. While it doesn’t always bear out, where would we be without the wisdom of crowdsources like Reddit, Quora, Wikipedia… or FanGraphs?

Beyond just being a fun way to engage with readers, the FanGraphs free agent crowdsource predictions exercise represents a good test of the “wisdom of the crowd” theory. Let’s see how wise this crowd turned out to be.

To test our wisdom, on February 17 and then again on March 8, I downloaded the excel file of the 2025 Free Agent Tracker. I then selected for every free agent who signed for a total contract value of at least $2 million, resulting in 105 cases. (Jon Berti and Amed Rosario just made the cut with one-year, $2 million deals; Mike Tauchman and Michael A. Taylor just missed it at one year and $1.95 million.) I then sorted out the players who didn’t receive a crowdsource estimate, reducing the pool to 67 players.

These 67 players were predicted by us to receive a collective 153 years of contracts (an average of 2.28 years per player) for a collective total of $2,886,520,000 and an average contract of $43,082,388.

However, this was an overall good year for free agents — just ask Juan Soto (15 years, $765 million) or Max Fried (8 years, $218 million) — and they ended up collectively out-earning our expectations by 10.4%. These 67 free agents signed a collective 150 years of contracts (we were 98.7% accurate in cumulative contract length!) for a collective $3,186,325,000, with an average contract of $47,557,090 (an AAV of just over $19 million).

Our collective wisdom was pretty good, but we underestimated the market by 10.4%. Let’s take a more detailed look at what happened.

Analyzing the Widest Prediction Gaps
In my research, I looked at the differences between what the FanGraphs crowd predicted and the actual signings. Again, I compared total contract value to the median crowdsourced prediction. (I know this is an oversimplification. I couldn’t think of an elegant way to include things like the “value” of opt-outs, etc.)

The FanGraphs crowd was within $2 million of the actual contract value for 22 of the free agents and got two exactly right, the one-year deals that Justin Verlander ($15 million) and Caleb Ferguson ($3 million) signed.

Some free agents signed for considerably more than we expected. In terms of total amounts, Soto, Fried, Blake Snell (5 years, $182 million), Tanner Scott (4 years, $72 million), Willy Adames (7 years, $182 million), and Corbin Burnes (6 years, $210 million) all exceeded their contract predictions by at least $30 million, with Soto, Fried, and Snell earning over $60 million more than we predicted. No other player signed a deal worth more than $20 million above what we predicted for him. Five relief pitchers — A.J. Minter (2 years, $22 million), Andrew Kittredge (1 year, $10 million), Yimi García (2 years, $15 million), Blake Treinen (2 years, $22 million), and Scott — netted contracts worth more than double what we expected they’d get. Minter especially scored a bonanza, getting a total value that was more than four times higher than what we predicted. It was a very good year to be a high-upside relief arm.

Notable Underestimated Contracts
Player 2025 Team Crowdsource Prediction Actual Contract Total Value Diff.
Juan Soto NYM 13 years, $585 million 15 years, $765 million $180 million
Max Fried NYY 5 years, $125 million 8 years, $218 million $93 million
Blake Snell LAD 4 years, $120 million 5 years, $182 million $62 million
Tanner Scott LAD 3 years, $36 million 4 years, $72 million $36 million
Willy Adames SFG 6 years, $150 million 7 years, $182 million $32 million
Corbin Burnes ARI 6 years, $180 million 6 years, $210 million $30 million
A.J. Minter NYM 1 year, $5 million 2 years, $22 million $17 million
Blake Treinen LAD 1 year, $8 million 2 years, $22 million $14 million
Yimi García TOR 1 year, $5 million 2 years, $15 million $10 million
Andrew Kittredge BAL 1 year, $3 million 1 year, $10 million $7 million

On the flip side, there were other free agents who signed contracts below our predictions, with many of these players settling for short-term deals that curbed their total values. Pete Alonso (2 years, $54 million), Jack Flaherty (2 years, $35 million), Ha-Seong Kim (2 years, $29 million), Alex Bregman (3 years, $120 million), and Gleyber Torres (1 year, $15 million) all received contracts that were worth at least $30 million less than we expected, with only one other player, Andrew Heaney (1 year, $5.25 million), underperforming his predicted deal by more than $14 million. In terms of percentage, Alonso, Flaherty, Kim, Torres, Heaney, and Max Kepler (1 year, $10 million) received less than 50% of what the crowd predicted. It’s worth pointing out that Alonso and Bregman received higher average annual values than expected, owing to their shorter contract lengths. Bregman is set to make $4.7 million more per year than the $27 million AAV the crowd predicted for him, while Alonso’s $27 million AAV is $2 million per year more than expected.

Notable Overestimated Contracts
Player 2025 Team Crowdsource Prediction Actual Contract Total Value Diff.
Pete Alonso NYM 5 years, $125 million 2 years, $54 million $71 million
Jack Flaherty DET 4 years, $88 million 2 years, $35 million $53 million
Ha-Seong Kim TBR 4 years, $73.5 million 2 years, $29 million $44.5 million
Alex Bregman BOS 6 years, $162 million 3 years, $120 million $42 million
Gleyber Torres DET 3 years, $54 million 1 year, $15 million $39 million
Max Kepler PHI 2 years, $22 million 1 year, $10 million $12 million
Andrew Heaney PIT 2 years, $25 million 1 year, $5.25 million $19.75 million

Eyeballing the data, a pattern seemed to emerge in which the top of the market did as well or better than expected, while the middle-to-bottom of the market fared worse. (This would be consistent with many author and reader hypotheses of how the market would shake out.) So I ran a quick correlation between the rank of the size of the signed contract and the difference between prediction and actual total contract value. The correlation coefficient was -.52, indicating that indeed those who signed the smaller contracts signed for less than predicted more so than those who signed larger total contracts.

The Implications of Signing Late
Once again, Ben pre-empted some of my analyses with his own deeper dives. Specifically, back in January, he examined whether those who signed late in the offseason (a) signed for less, and (b) performed worse than those who signed earlier. In short, yes and yes.

When one of my favorite players, Alonso, signed late and for far less than we expected, I also hypothesized that those who sign late in free agency get less than expected relative to those who sign early. After all, late signees usually do so after their options have dwindled. However, the 2025 free agent tracker does not include date of signing, so I could not directly test this proposition. (I suppose if I’d really wanted to spend time researching this, I could have gone back and logged every signing date, but, you know, this is the Community Blog and not my full-time job.) That said, I did find the list of players who’ve signed since the start of February as opposed to earlier in the offseason and ran some quick comparisons.

Of the players in the main sample, nine signed between February 1 and March 8. Nick Pivetta, Enrique Hernández, and Tommy Pham all signed for more than expected, although Hernández and Pham signed one-year deals worth $1.5 million and $1 million above their modest one-year expectations. Pivetta signed for an additional year and $10 million over his predicted deal (5 years and $55 million, compared to the crowd’s prediction of 4 years and $45 million). Kanley Jansen (1 year, $12 million) and Justin Turner (1 year $6 million) signed one-year contracts worth $2 million less than we expected — not very far off expectations.

The remaining four deals since the start of February demonstrate the downside of signing near the end of the offseason. In fact, those four players (Bregman, Alonso, Flaherty, and Heaney) represent four of the six deals listed in the overestimated contracts sample included in the previous section.

Comparison to Six Years Ago
Back in 2019, I performed a similar analysis that was published here in the community notes. That year’s free agent class, led by Bryce Harper and Manny Machado, came in under our expectations. Recall 2019 was a very cold “hot stove,” with major signings not occurring until late in the offseason. (Harper wasn’t signed until February 28!)

We predicted that year’s sample of 47 free agents would receive a collective 123 years of contracts (an average of 2.61 years per player) for a collective total of $1,801,000,000 and an average contract of $38,320,000. However, they ultimately received 91.4% of what was expected – a collective 109 years of contracts (an average of 2.32 years per player) for a collective total of $1,619,500,000 and an average contract of $34,460,000.

Our collective wisdom back then was also pretty solid, except we overestimated the market for free agents by just about the same margin as we underestimated it this year.

Conclusions?
I don’t think we can take any major lessons from this analysis — perhaps just two small ones: 1) relief pitchers with upside did well, and 2) prominent free agents shouldn’t wait too long to sign. That said, running the numbers was fun, and I hope you enjoyed the article. I’ll be back next year at this time with another update. Until then, let the wisdom of crowds protect you from the madness of crowds.


Joint Model of the WAR Aging Curve

An aging curve illustrates how a performance changes throughout a career. It plays a crucial role in various fields of baseball, particularly in player evaluation and forecasting. While any performance measure could theoretically be the subject of an aging curve, we will focus on WAR hereafter. This is because WAR captures a player’s actual playing time. No player can help his team win while sitting at bench (or hospital).

Before we get into the technical stuff, let’s talk about what we pursue, or expect from an aging curve. I expect an aging curve to be the average trajectory of players. In other words, I expect a player to follow the trajectory over his career.

Keep in mind that this is not the same as simply the average WAR of all player-seasons at each age. That approach would be valid only if players started and ended their careers at the same ages. But that is not the case.

Consider this example: Imagine a league established in 2015 with two distinct groups. As of 2015, half of the batters are ordinary players in their age-20 seasons, while the other half are 30 but very talented. If we track these players until 2024 and average their player-season WAR by age, we’d get a curve spanning ages 20-39. But this curve does NOT represent a single player’s trajectory, since two parts of the curve (20-29 and 30-39) are constructed from whole different populations.

Below is the crude aging curve of batters, constructed by simply averaging each batter-season WAR by age. I looked at the player-seasons of the Statcast era (2015-present, excluding 2020), and includes all primary position non-pitcher players with at least one plate appearance. To keep the sample size reasonable, I only looked at players 21-35 years old.

In this injury-epidemic era, not being hurt is getting increasingly important. To account for this, I imputed a WAR of zero for a player who missed an entire season if he has a record in the majors both before that missed season AND after that missed season.

Take Fernando Tatis Jr. as an example. He missed all of 2022 due to injuries and his PED suspension, and because he played both before and after 2022 (2019-21, 2023-24), I counted his 2022 WAR as zero. (This is a small bonus of using WAR. We can easily impute zero to these seasons. With other stats like wRC+, picking a value to fill in would be much trickier.)

In this crude model, players peak at age 30 with a WAR of 1.2. This might look different from aging curves you’ve seen before.

The point of this is to account for the fact that players debut and retire at different ages. Previous research tackled this by looking at WAR differences between consecutive seasons for individual players. Here’s how it works: Take Shin-Soo Choo, who posted 0.5 WAR at age 33 and 0.3 WAR at age 34. That -0.2 WAR difference becomes one data point for the age 33-to-34 change. In contrast, Félix Hernández’s final season came at age 33, so we do not use his data to calculate 33-to-34 difference. This way, we’re comparing players to themselves, using the same group of players for each year-to-year change. (Note that the mean of differences is the same as the difference of means, if the population is fixed.)

This “difference method” helps with the population mix problem, but it’s not perfect. We run into trouble when comparing changes across multiple years because we’re dealing with different groups of players. Let’s say we use 100 players to find the average WAR change from age 33 to 34. When we look at the change from 34 to 35, we’re working with a different group – not even necessarily a subset of those original 100 players.

This all comes back to players starting and ending their careers at different times. If everyone played from the same age to the same age, we’d have consistent groups to compare. Even with varied career lengths, it would work if retirement and debut ages were totally random – like if they were decided by flipping a coin rather than being tied to how well a player performs. But that’s not how baseball works – performance definitely affects how long players stay in the league.

Let’s try a different approach to building an aging curve. Instead of just averaging WAR (or difference of WAR) by age, we’ll use what is called a mixed effects model. This is great for our purposes because it can handle a correlation problem: A player’s performance in one season tends to relate to his performance in other seasons. For example, Choo’s WAR at age 33 is definitely related to his WAR at age 34, but not related to the 3.1 WAR Nolan Arenado put up last season at age 33. Assuming the quadratic curve of WAR by age, I fitted a model like this:

WAR_i = β0 + β1age + β2age^2 + b0i + b1iage

The subscript ‘i’ represents a player. The model has two parts for each player:

Part 1: b0i is called “random intercept” and represents how much a player i is departed from the average player.

Part 2: b1i is called “random slope” and represents how much a player i’s rate of change by age is different from the average player.

But usually, those “random effects” are not of primary interest and considered to have a mean of 0. What we really want is the average trend. That comes from the β values, which turned out to be: β0 = -15.46, β1 = 1.20, and β2 = -0.02. I plotted these values to create the aging curve below. Note that I used a different color for ages above 35 since those are not based on the data, but extrapolated by the model.

Using this model, we find players peak at age 27.2 – three years earlier than what our crude model suggests. But we’re still running into the same issue we had with the difference method: survivor bias.

The players who stick around into their mid-30s aren’t your average players – they’re usually the most talented ones who can still perform at a high level. So when we look at the numbers for older ages, we’re really just looking at the success stories, which makes our estimates too optimistic. This is well illustrated by the pitchers. If we draw a crude WAR average graph, it has a peak at age 34! (For pitchers, any player of primary position pitcher, with at least one total batter faced was included in the study.)

Previous studies tried to handle this bias by making educated guesses about what players would have done if they hadn’t retired early. For example, if a player retired at 34, researchers would estimate what his WAR might have been at 35 and include that in the analysis.

But there’s another approach: using what’s called a joint model. As the name suggests, this combines two different models: 1) A longitudinal model that tracks how WAR changes with age, and 2) A survival model that looks at how WAR affects when players retire.

Instead of just looking at how players age OR just looking at who stays in the league, we’re considering both at the same time. This gives us a much more complete picture of player aging.

I’ll omit the technical details. I used an R package called JMBayes. Below you can see how this joint model compares to our simpler naïve model.

The blue curve is the naïve model, and the red curve is the joint model. The peak of batter is at age 26.5 in the joint model, approximately 0.7 years earlier than the one by the naïve model. Below are the curves for pitchers. The peak was at 26.8 in the joint model, 0.9 years earlier than the peak at the naïve model (27.7). (Just remember that any values shown beyond age 35 are projections based on our model, not actual data.)

This is all I want to introduce.

But one more thing. Should we adjust for the survivor bias at all?

The answer depends on what you’re trying to figure out. Let’s look at two common scenarios:

Scenario #1: If you’re trying to predict how a 34-year-old free agent pitcher will perform this year, the unadjusted difference method works just fine. After all, this pitcher is still in the league, so we know he has “survived” to this point.

Scenario #2: But if you’re projecting a 20-year-old prospect’s career path, you definitely want to use the adjusted model. Here’s why: The unadjusted aging curve is actually showing you two different things. The data for players in their 30s only includes the most talented players who stuck around, while the data for players in their 20s includes pretty much everybody who made it to the majors. So you end up with a curve that doesn’t truly represent either group – it’s not showing you the path of an average player OR the path of a star player.

One final note about the difference method that’s easy to misinterpret: When it shows something like “WAR decreases by 0.3 between ages 34 and 35,” that’s what statisticians call a conditional difference. This means “IF a player is good enough to still be playing at both age 34 AND age 35, he typically declines by 0.3 WAR.” It’s not telling you about all players who reached age 34 — just the ones who kept playing through 35.


It’s Time To Buy Into Cristopher Sánchez

Bill Streicher-Imagn Images

“One for the Money. Two for the Show.” That’s how the saying goes anyways. And that’s how Cristopher Sánchez’s career has gone thus far.

After a stretch of 33 starts from 2023 through mid-June 2024, in which the lanky lefty compiled 183 2/3 innings of a 3.09 ERA, he was really into the money, to the tune of a four-year, $22.5 million extension – with room to grow to six years and $56.5 million with incentives and club options.

He followed up this showing with 15 more strong starts, along with a five-inning performance in Game 2 of the NLDS, the Phillies’ only win against the Mets, to put a bow on his second year as a rising star in the majors.

But why isn’t he treated as such? You won’t often find the 28-year-old gracing MLB’s Instagram account, or even Pitching Ninja’s for that matter. He is not marketed as an ace despite his relative youth, place in a big-market postseason rotation, and proclivity to go deep into games.

Maybe the better question is, why should he be? I’ve decided to take up that mantle, at least within the friendly confines of the FanGraphs Community Blog.

For starters (pun definitely not intended), Sánchez carries a modern ace workload. Across 31 starts in 2024, Sánchez reached 181 2/3 innings. Like a true ace, he faced 24.32 batters per start – for context, this lines up with the volume of notable innings eaters Corbin Burnes and Tarik Skubal, and was certainly in the upper echelon of 2024 starting pitchers.

So, he faced a lot of batters. He also eclipsed 90 pitches per start. Both of these statistics matter because, to an extent, the best ability is availability. Cliché, sure, but true for postseason hopefuls like the Phillies, and true when it comes to staying at the top of fans’ minds. Put differently, Sánchez’s 3.32 ERA was stretched over more innings than most starters in the league threw last season. That is valuable.

Under the hood, the most notable pieces of Sánchez’s profile are his sky-high 39.3% O-Swing% (Sports Info Solutions) and solid 65.8% first pitch strike rate. That 39.3% O-Swing% was good for first in baseball last season. That’s right: Cristopher Sánchez – League Leader. Let that sink in.

As I mentioned earlier, Sánchez is not thought of as a particularly nasty pitcher. His stuff is not commonly GIF’d. He is relatively obscure, as far as sub-3.50 ERA starters on playoff teams go. Yet, he clearly stands out, especially when it comes to generating swings on pitches outside of the zone.

So how does he generate all of this chase? And why aren’t we calling him Chasetopher Sánchez (that may be more obvious)?

Sánchez throws three pitches according to Baseball Savant: sinker (47.3%), changeup (35.7%), and slider (16.9%). And he generally throws them all low in the zone.

This makes sense. He is a groundball specialist, generating a 58.3% groundball rate last season, good for a 95th percentile finish and the consequent bright red bar on his Savant page. And if we all are trained to do one thing, it’s to love when a player has bright red on his Savant page. It’s akin to a “Happy Hour” sign in a bar window or “BOGO” sign at the deli. It’s the modern day siren song. How could you not follow it?

The graphic above shows Sánchez’s three primary pitches and plots only those that generated swings and misses. Clearly, changeups below the zone make up the vast majority of his impressive O-Swing%, followed by sliders below the zone.

Sánchez threw his changeup outside the zone 71.8% of the time last season when ahead in the count (compared to 51.1% of the time when behind) and threw sliders outside the zone 60.4% of the time when ahead. Another note – the changeups in these situations skew glove side, while the sliders skew arm side.

Here was a particularly nice changeup thrown to Freddie Freeman in a 1-1 count.

This same pitch and location worked against lefties and righties. See the following string-pull presented to Aaron Judge.

The changeup plays well off of the sinker, his most commonly thrown pitch. There is a nearly 10-mph velocity gap between the two offerings, and both come from the same arm angle and have nearly identical arm-side tail. In other words, this is a nasty pitch, which is borne out in the 18 run value that the pitch generated in 2024, according to Baseball Savant.

Sánchez is elite at generating chase swings, likely because his best pitch is spotted to do just that. But part of why he may not get the consequent publicity his ERA would suggest he deserves is because, even as he gets all those swings on pitches outside the zone, he doesn’t miss as many bats as other high-chase hurlers.

Cubs lefty Shota Imanaga and Twins righty Bailey Ober finished second and third in O-Swing% last season, respectively. Both also allowed less contact on pitches in the zone and generated more swinging strikes than Sánchez. Not surprisingly, thanks to these whiffs, both struck out more batters than Sánchez as well.

Top Chase Starters, 2024
Name Team O-Swing% O-Contact% Z-Contact% SwStr% K%
Cristopher Sánchez PHI 39.3% 67.2% 86.5% 11.3% 20.3%
Shota Imanaga CHC 38.9% 60.0% 83.0% 14.5% 25.1%
Bailey Ober MIN 37.1% 63.2% 79.7% 14.2% 26.9%
SOURCE: Baseball Info Solutions

I think this is, in part, because Imanaga and Ober are fly ball pitchers whereas Sánchez is a ground-and-pound specialist. Famously, balls hit in the air come with a greater risk of going over the fence than grounders, so the best way for Imanaga and Ober to avoid damage is to miss bats. Sánchez, though, can get away with pitching to contact, which can help to keep his pitch count down and allow him to go deeper in games.

Top Chase Starters, 2024 Batted Ball Data
Name GB% FB% HR/9 K/9
Cristopher Sánchez 57.4% 21.5% 0.54 7.58
Shota Imanaga 37.2% 45.5% 1.40 9.03
Bailey Ober 33.5% 50.3% 1.36 9.62

Considering this, the better comparison for Sánchez is another Dominican lefty with an affinity for the sinker: Framber Valdez. Sánchez doesn’t have the pedigree of the Astros ace, but their arsenals and pitching approaches are similar.

Cristopher Sánchez and Framber Valdez, 2024
Name Team ERA FIP GB% Si% O-Swing% SwStr%
Cristopher Sánchez PHI 3.32 3.00 57.4% 47.3% 39.3% 11.3%
Framber Valdez HOU 2.91 3.25 60.6% 47.1% 31.2% 11.4%
SOURCE: Baseball Info Solutions

What’s perhaps even more interesting about this comparison is Valdez’s embrace of the changeup in 2024, as pointed out by Ben Clemens this offseason.

Last season, Valdez threw the changeup in two-strike counts nearly 20% of the time, compared to 13.9% in 2023 and less than 10% of the time in all other prior seasons. Sánchez, meanwhile, threw changeups 51.4% of the time with two strikes last season. This makes plenty of sense, as the pitch generated a healthy 17.8% swinging strike rate.

So perhaps both have something to learn from each other, with Valdez leaning more into the changeup and Sánchez learning from new teammate Jesús Luzardo on his breaking stuff – wouldn’t that be fun? Even more likely, perhaps both are poised to continue frustrating opposing hitters with their bowling ball sinker/change combinations.

Ultimately, for as much love and attention as Valdez has earned at the top of Houston’s rotation, I think it is about time “Chasetopher” catches on and Sánchez gains a bit of respect as an emerging ace.


Does Consistent Messaging Impact Pitcher Performance?

Wendell Cruz-Imagn Images

Editor’s Note: A version of this post was first published on Liam Delehanty’s personal blog on Medium.com.

As someone whose playing career fizzled out after high school, the realm of scouting and player development is one that has always drawn my interest. With the tools that MLB organizations and third-party facilities like Driveline and Tread Athletics utilize, it is easier than ever for players look at their unique biomechanical profiles, identify areas of improvement, and optimize everything from their spin rates and movement profiles to their throwing workloads. Despite the ability to objectively evaluate such a wide range of player traits, drafting and development remains an inexact science, with 26% of signed draftees between 2012–2019 reaching the majors, and only 3% of drafted players contributing more than 5 WAR with team that drafted them. (For reference, Dillon Gee generated 5.0 WAR over the course of his MLB career.) What gives players the ability to reach or exceed their potential? What makes certain organizations (Astros, Dodgers, Rays) more likely to develop major league contributors, while others consistently struggle to do so?

In recent years, organizations have made more concerted efforts to bridge the gap between analytics and traditional coaching, with former players like Brian Bannister serving as conduits between the front office and on-field staff. Bannister described much of his role as VP of Pitching Development with the Red Sox as “…during a bullpen session, holding my phone and showing it to a pitcher, showing him what the data says and then telling him why I think he should make an adjustment and backing it up on the spot.” Despite the industry shift toward a more player-friendly deployment of data, Driveline’s Kyle Boddy believes “player development departments are still highly fractured — there is strong resistance in most organizations to unify under a data-driven message.”

Motivated by my interest in the field and a Saberseminar presentation in 2023 by Katie Krall, which emphasized organizational efforts to fight “stereo coaching” and deliver a consistent message around a player’s development plan to all levels of the organization, I am examining if it is possible to find a link between organizational consistency and performance relative to projections. This study formed the basis of my 2024 Saberseminar presentation, titled “Consistency is Key? Examining Pitcher Arsenals Across Organizations.”

Org Level

Given publicly available data, I decided to use pitch arsenals as a proxy, as Statcast added Triple-A pitch-level data in 2023. Pulling team-level statistics and differentiating by pitch type percentage, we can get an overview of which organizations had the closest alignment in pitch arsenals across Triple-A and MLB.

From the data above, we can see that the Giants, Nationals, and Marlins saw the greatest overall difference in arsenals across Triple-A and MLB, while the Braves, Mets, and Orioles had the most consistency across levels. Did this impact how the staff performed relative to projections? To examine this, I pulled year-end individual statistics for the 2023 season, and compared them to preseason PECOTA projections, grouped by team. I then calculated correlations between the delta in pitch category and average difference in actual ERA, FIP, WHIP, and DRA vs. projections by team, then further broke out the data into plots for WHIP and DRA, the two metrics with the (relatively) strongest correlations:

While all of these correlations range from weak to nonexistent, the inverse nature of the correlations suggests there may be a small relationship between greater variance in arsenals across levels, and better performance compared to preseason projections. While a variety of other factors can play into this, it aligns with the idea that the most successful organizations are not those that necessarily preach one message across levels, but can identify and implement tweaks throughout the season.

If we are able to get more granular with these data, can we identify a more solid relationship between arsenal variance and performance?

Player Level

As a next step, we will be looking at a subset of players who spent significant time in Triple-A and MLB to see if there is a stronger relationship between individual arsenal variance and performance. Using Python, I gathered a list of pitchers who had thrown at least 100 pitches in both Triple-A and MLB during the 2023 season. (Apologies to the Alex Wood lovers, he fell one Triple-A pitch short of making the dataset.) With a group of 395 pitchers, I calculated the pitch percentage difference for each pitch category (fastball, offspeed, breaking, other) in a player’s arsenal by taking the absolute difference of pitch percentages of each pitch category in Triple-A and in MLB and calculating a total and average difference. For example, Logan Allen’s 2023 season broke down to a 14.35% total arsenal difference and a 3.59% mean arsenal difference.

Across the entire dataset, the median of all Total % Difference is 13.44% and the Average % Difference is 3.36%.

Performance vs. Projections

To measure if a smaller variance in arsenal aligned with stronger performance relative to projections, I pulled statistics from 2023, and compared them to Baseball Prospectus’ 50th Percentile PECOTA projections for each player, focusing on ERA, FIP, WHIP, and DRA. For both the total and average pitch percentage differences, our correlations ranged from incredibly weak to nonexistent. Total and Average % Difference were perfectly correlated, as evidenced below. The results show that these correlations were even weaker than those found at the organization level.

A Sample: Organizational Philosophy in Player Acquisition

Finally, let’s look at three organizations with notable philosophies or histories of pitching development, to see what we could glean from the types of players they acquire and subsequent tweaks to pitcher arsenals. First, we’ll start with the Red Sox, for their anti-fastball approach. Then, we’ll go to the Yankees, due to their history of developing pitchers both internally, Luis Gil for example, and those acquired externally, like Clay Holmes. Lastly, we will look at the Dodgers, as their decade-long run of success has been sustained by their ability to, in the words of Noah Syndergaard, “turn everything they touch into gold.”

For this portion, I looked at players acquired by these three organizations between May 1 and August 1 of 2024. This range was selected to exclude any offseason arsenal tweaks that the pitchers may have made, and to isolate changes to those that can be attributed directly to the shift in organizations. While this is a relatively small sample size, certain trends do begin to emerge:

The Red Sox tend to acquire pitchers with four-seam fastball usage roughly at league average, and, true to form, reduce that number drastically to 19%. This difference is made up through more than doubling usage of the cutter, while also increasing the frequency of the sinker.

Unlike their AL East rivals, the Yankees employ a different tact — acquiring pitchers with lower four-seam usage relative to league average, and increasing that along with slider percentage — encouraging their acquisitions to lean on higher-velocity offerings, while decreasing the overall usage of breaking and offspeed pitches.

Over on the West Coast, the Dodgers have acquired pitchers who are heavily four-seam dependent (driven by Michael Kopech’s MLB-leading 79.1% four-seam usage) and encouraged a more diverse pitch mix, boosting sinker usage by almost 5 times, and adding one of the league’s two screwballers in Brent Honeywell.

What Can We Take From This?

In short, this analysis shows us that there is no meaningful relationship between arsenal consistency across levels and performance relative to projections at either the organization or individual player level within the same season. What we can deduce from this is that organizational philosophies can be discerned from a player acquisition level, and this can be used to identify pitchers who may be able to unlock another level of performance if they are put in the right situation. For example, the Red Sox maximize usage of a pitcher’s secondary offerings, which can cover up a poor fastball, while the Yankees seek out pitchers who could stand to benefit from leaning on their pure velocity and stuff to boost the fastball/slider combo.

Additionally, there are many more avenues that can be explored in this area. Is there an even smaller subset of players that should be considered? Can we focus on performance across specific pitch types? Would performance across seasons be more telling? Are there other proxies that would work better than pitch arsenals?

Fundamentally, what makes this such an inexact science is the fact that it’s difficult to measure! Even if there is not publicly available player performance data to back up the notion, entire industries in the business world have been built around ‘breaking down silos’ within organizations, and there is no reason why baseball should be an outlier in that regard.


Starting Pitchers Aren’t Leaning On Their Best Pitches

Nathan Ray Seebeck / USA TODAY Sports

The title of this post does not exactly mince words. Should that be all the context you need (TL;DR), it would be fair to move on. However, for those looking for a greater explanation, qualifications and nuance abound in what follows as justification for such a statement.

The impetus for doing some digging and eventually choosing this topic (and title) is pretty simple; I wondered whether starting pitchers, over the course of a long season, throw their best pitches more often than their less effective pitches.

Starters were the focus for a reason. Relievers, who most often face mere subsets of an opposing lineup (and face that subset crucially just once) in any given outing, are likely more inclined to defer to their strongest offerings at higher rates. Starting pitchers, meanwhile, often have to grapple with the phenomenon of diminishing returns on pitch usage. Should an opposing hitter see that “best” pitch over and over, what made it effective in the first place loses some of its value to a hitter’s heightened recognition. Starting pitchers, it turns out, probably should practice some moderation.

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How Does Seiya Suzuki Stack Up?

Yukihito Taguchi / USA TODAY Sports

With Japanese outfielder Seiya Suzuki signing with the Chicago Cubs (written about by Kevin Goldstein here while Dan Szymborski ran projections on him here), I wanted to compare him to other Japanese position players who have moved to MLB in recent years. The comparisons I made were to the final NPB years of Shohei Ohtani, Yoshitomo Tsutsugo, and Shogo Akiyama. But considering Ohtani was injured in 2017, his stats will be from both the 2016 and 2017 seasons. Data is based on 1.02 – Essence of Baseball public data managed by DELTAGRAPHS.

Comparing Recent Japanese Position Players’ WAR
Player Year PA Batting Base Running Fielding Pos WAR
Shohei Ohtani ’16 382 33.2 3.4 -0.2 -5.9 4.4
Shohei Ohtani ’17 231 15.9 0.3 0.2 -5.2 1.9
Tsutsugo Yoshitomo ’19 557 23.3 -1.5 -16.7 -9.8 1.3
Shogo Akiyama ’19 678 31.0 2.3 -4.3 4.7 5.6
Seiya Suzuki ’21 533 57.6 -0.4 11.2 -4.4 8.6

Suzuki posted 8.6 WAR in 2021, the best for position player last year. His high WAR is based on great batting value (+57.6 per 500 PA), higher than Ohtani (+43) and twice that of Tsutsugo (+21) and Akiyama (+23). His baserunning value of -0.4 is average in NPB, and his total baserunning value of +1.4 from 2019-2021 is neither good nor bad. Meanwhile, he is a good right fielder, putting up a fielding value of +11.2 (equal UZR). Tsutsugo (-16.7) is a left fielder and Akiyama(-4.3) is a center fielder, so we cannot simply compare them, but I think we can expect better fielding stats than Tsutsugo in MLB. Read the rest of this entry »


The Last Solo Umpire

Kyle Terada / USA TODAY Sports

July 11, 1923, was a sunny, seasonal day in Philadelphia. As National League umpires, Ernie Quiqley and Cy Pfirman were accustomed to living out of a suitcase and spending nights and game days in Philadelphia, Brooklyn, Manhattan, Boston, Pittsburgh, Cincinnati, Chicago, and St. Louis. Quigley had been at this for more than a decade, starting his NL career in 1913; the first of the day’s games was the 146th that he’d umpired in Philadelphia. And while it was only Pfirman’s second season, he’d already worked 24 Phillies home games. On this day they were going to work a doubleheader, which was unusual but not extraordinary for a Wednesday, as the Cincinnati Reds were in town to play their regularly scheduled game followed by a makeup of the May 15th tilt that had been rained out.

The two umpires had been paired up since the season started on April 17th, having worked 70 games together over the first 85 days. As the more veteran member, Quigley was clearly the “chief.” Of those 70 games, he had been the home plate umpire in 68, even presiding over the plate in both ends of five doubleheaders. That’s how it had worked with Major League umpires since professional baseball started. In the early days, a single umpire worked most games. 1909 was the first NL season that had more games worked with two umpires than one, 442 games to 179. By 1910, the single-ump game had nearly been eliminated altogether, with less than 10 such games every year. Most of those rare solo games were necessitated by travel constraints — it was hard to get a person from far-flung St. Louis after a game to the east coast for another game the next day. Prior to 1923, there hadn’t been a game worked by only one umpire since 1917. In fact, the NL had begun incorporating three umpires into games occasionally in 1917.

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What Makes a Good Four-Seamer Good?

There used to be a lot of debate about the four-seam fastball and the relationship of velocity, vertical movement, and spin rate. But now there is a new concept called Vertical Approach Angle (VAA) that includes the height of the release and the height of the pitch’s path. With that in mind, let’s think again about what is needed for a good four-seam fastball.

Cross-Tabulating To Determine the Impact of Each Element

A cross-tabulation was performed for four-seamers thrown in MLB from 2017-2021, with velocity ticked to 4 km/h, vertical movement ticked to 7.5 cm, release height ticked to 10 cm, and plate height ticked to 15 cm. Each element was tabulated and color-scaled with the MLB average as the middle value in white, good values for pitchers in red, and bad values in blue. The indicators are Whiff%, xwOBAcon, and xPV/100 (expected Pitch Value per 100 pitches, which I wrote about here). Read the rest of this entry »


Are Hitters Hitting It Where It’s Being Pitched?

If you watch basebll games, which you probably do if you find yourself reading this, then you’re likely familiar with announcers employing phrases like “he just went with it,” or “hit it where it was pitched.” These phrases suggest hitters have made contact with the baseball such that outside pitches are hit to the opposite field and pitches on the inner half are put in play to the hitter’s pull side.

These comments beg the question: are hitters “going with” the pitches they are thrown with any discernible frequency? In today’s game, wherein the value of tapping into pull power and raising average launch angles has been well established, are hitters still hitting it where it’s pitched? To what extent do team’s defensive alignments correspond to how their pitchers will approach any given hitter should that hitter go with pitches? Given that pitchers who throw higher in the zone more often allow fly ball contact and those who throw lower induce more groundballs, does something similar apply for hitters given how they are pitched on a horizontal plane, i.e. inside and outside? Read the rest of this entry »


A Peta Perspective on the Hot Stove So Far

Cold snowy days here in our nation’s capital, combined with the owners’ and players’ seeming determination to kill the golden goose, provides an opportunity for me to look at the hot stove (pre-lockout) through the lens of the Peta methodology. For those unfamiliar with the Peta methodology, I refer you to this deeper dive here on the Community Blog published last January. Based on Joe Peta’s groundbreaking 2013 book Trading Bases, the methodology derives each team’s upcoming season win-loss record based on the utilization of its previous season performance (runs scored/runs allowed), adjusted for cluster luck (my proxy is FG BaseRuns), and the team’s upcoming-season projected WAR.

Just before Opening Day, the product of this calculation is compared to the money line. Peta suggests that in a 162-game season, win totals produced by the model that deviate from the money line by more than four games (1.5 games in a 60- game season) represented “unrepeatable results” and therefore were worth a possible wager. Read the rest of this entry »