Archive for Featured

Chad’s Mistakes Made, Lessons Learned

Credit: Joe Nicholson-Imagn Images

Chatting with Jake Mailhot about our plans for the off-season, he mentioned something his kid talked about: learning from her mistakes. First of all, that’s some A-plus parenting, Jake. But then Jake took it a step further and suggested that if his daughter could learn from her mistakes, so could we. So here are five numbers that represent mistakes I made this year and the lessons I learned.

Read the rest of this entry »


The Balance Between Called Strikes and Chase

Sep 15, 2025; Tampa, Florida, USA; Toronto Blue Jays pitcher Brendon Little (54) throws a pitch against the Tampa Bay Rays in the sixth inning at George M. Steinbrenner Field.
Credit: Nathan Ray Seebeck-Imagn Images

In early June, Alex Chamberlain graced us with a FanGraphs article about Brendon Little and a new concept called, “Implied Miss Distance”. Chamberlain, along with Baseball Prospectus writer/researcher Stephen Sutton-Brown, have done some great work utilizing Statcast bat tracking data, giving readers a new perspective on something like a swing and miss. But, back in early July, nearly a month after Chamberlain wrote about Little’s amazing knuckle-curve and it’s ability to make hitters whiff so hard that the outfield flag flutters, hitters stopped chasing the pitch. They were tired of looking silly and would no longer budge, allowing us to imply nothing:

A Rolling Line Chart of Brendon Little's O-Swing% 2025

If it wasn’t for Chamberlain’s article, I wouldn’t have known about Little or his knuckle-curve. But that’s why FanGraphs is the best, and when I recently watched the Blue Jays and their relievers’ deteriorating August WHIP, I heard the broadcasters mention Little’s falling O-Swing, or chase, rate.

If you only focused on Little’s knuckle-curve and the damage hitters have done to it in each month of the season, as you see in the table below, you wouldn’t think twice about the pitch’s performance:

Little’s Knuckle Curve by Month 2025
Month KC Total Pitches KC% wOBA
Mar/Apr 96 218 44.0% .194
May 111 229 48.5% .176
Jun 119 243 49.0% .212
Jul 103 193 53.4% .192
Aug 76 193 39.4% .146
Sep/Oct 51 119 42.9% .257

Among pitchers who have thrown at least 100 knuckle curves in any of the last five seasons, Little’s 2025 wOBA of .188 is a fringe top 20 (25th) out of nearly 200 pitchers. Last season, Little got even closer to the top 20 mark (23rd) with a .186 wOBA on the pitch. But the broadcast never said anything about Little getting hit; they were focused on the lack of chase and, therefore, an increased BB%:

A rolling chart of Brendon Little's Chase%/BB% 2025

The chart above includes all of Little’s pitches. By isolating the O-Swing% to only his knuckle-curve, we can see that this overall drop in hitters’ chasing after Little’s offerings wasn’t solely because of them spitting at that specific pitch:

A rolling chart of Brendon Little's Knuckle-Curve Chase% 2025

Thanks to the incredible addition of the Pitch-Type Split Leaderboard by the FanGraphs web team, we can now view the averages of individual pitches with ease. In 2025, among all pitchers who have thrown at least 10 knuckle curves, the league average O-Swing% currently sits at 35.5%. Little’s mark on the season is 36.5%. Rolling averages are different from season averages, and when Little’s chase rate rolling average dipped, so did the chase rolling average of his two other pitches:

A rolling chart of Brendon Little's Individual Pitch Chase% 2025

Chart 4 – Rolling KC, FC, SI Chase% Comps

The straight red line indicates times when Little stopped throwing his cutter. It’s interesting to see how the line stopped running horizontally around the same time his knuckle-curve was at its worst. Unfortunately, it didn’t fill the chased pitch gap, and that 40-50 game mark fell around early to mid-July when Little’s WHIP went upwards:

Brendon Little’s Monthly Splits (All Pitches)
Month KC% WHIP K-BB%
Mar/Apr 44.3 1.31 26.8
May 48.5 0.98 17.3
Jun 49.0 1.42 15.7
Jul 53.4 1.60 21.3
Aug 39.4 1.65 0.0
Sep/Oct 42.9 1.65 10.0

Hitters weren’t getting boosted wOBA’s from Little’s lack of chase, but the 1.65 WHIP  (5.97 eqiuv. ERA) meant they were hitting his other pitches and walking more. I’ve been rambling on about Little for more than a few paragraphs now, and you’re probably waiting for the point. The point? The point is, pitchers need to adjust when a pitch that used to be chased no longer gets chased. They know that. We know that. Yet, it’s difficult to keep track of on the fan side of things. Pitchers will go about adjusting in all sorts of ways.

In Little’s case, it was really just a blip. If you go back up to the graph showing individual pitch chase rates, you may notice that Little’s usage of the cutter, even if it wasn’t chased, allowed the chase rate on his knuckle-curve to jump back up. Hitters did a great job of laying off Little’s knuckle-curve from around games 30 to 70, but excellence is when a pitcher can adjust in the moment to hitters. That’s robotic. So, let’s!…get!…robotic! For the remainder of this article, I’ll present a detection system that can run daily to capture when a pitcher’s most used fastball and most used secondary are in good or bad rhythm using individual pitch plate discipline metrics. Here’s an example from Little’s 40 to 80 game span:

Categorizing Brendon Little’s Plate Discipline Balance
Game Number Rolling_CStr%_SI Rolling_Chase%_KC Performance
41-50 26.8 23.4 Ok (Adjusting)
51-60 21.1 25.8 Bad
61-73 16.9 21.8 Bad
SI Median CStr% = 24.5%
KC Median Chase% = 26.8%

The table is just a summary of what you see in Chart 4 above, but it’s designed to be placed in an automated system. If chase is up on one pitch and called strike is up on another, that’s good. If both pitches are falling to generate either chase or called strikes, well, that’s bad. Categorizing the balance between his sinker’s called strike rate and his knuckle-curve’s chase rate is as simple as creating rule-based logic:

conditions = [
(final_df['Rolling_Chase%']-3 > final_df['smart_median_chase']) & (final_df['Rolling_CStr%']-3 > final_df['smart_median_cstr']),
(final_df['Rolling_Chase%'] <= final_df['smart_median_chase']) & (final_df['Rolling_CStr%'] >= final_df['smart_median_cstr']),
(final_df['Rolling_Chase%']+3 < final_df['smart_median_chase']) & (final_df['Rolling_CStr%']+3 < final_df['smart_median_cstr']), (final_df['Rolling_Chase%'] >= final_df['smart_median_chase']) & (final_df['Rolling_CStr%'] <= final_df['smart_median_cstr'])
]
# Define the corresponding categories
categories = [
'Excellent',
'Ok (Adjusting)',
'Bad',
'Ok (Adjusting)'
]

Using the pitcher’s median values allows the categorization to detect improvements by each individual. I’m using “smart” medians to call the league median if a player has a zero value. That happens when they haven’t generated any chase or called strikes. If we use Brendon Little’s game logs to isolate his performance during those game periods from the table above, we see some pattern in a very small sample:

Brendon Little’s Overall Performance in Small Samples
Game Number WHIP K-BB%
41-50 0.91 32.3%
51-60 2.10 0.0%
61-73 1.33 15.4%

Little was at his best when he was in decent balance. This is the type of tracking that could be useful when streaming pitchers or looking for hot relievers. To test this out on a grander scale, I built a dataset that includes data from the last two months. This keeps the sample limited to more recent performance. Furthermore, I limited the data to only pitchers with more than 60 total pitches thrown in that time. Then, I took each pitcher’s most utilized fastball by pitch percentage and used it to calculate their called strike rate. I did the same with each pitcher’s most utilized offspeed, or non-fastball, pitch and used it to calculate their chase rate. I then calculated each pitch’s 15-game rolling rate, called strike for fastballs and chase for non-fastballs, and labelled their performance balance. Finally, I counted the number of days in which a player has been either good (balanced) or bad (unbalanced) and found the current status of players in both groups:

Players With Excellent Balance
Player Rolling CStr% Rolling Chase% Days of Excellence
Emilio Pagán 14.4 31.7 5
Dennis Santana 32.1 24.3 2
Tanner Scott 14.0 22.3 2
Jared Koenig 32.2 22.0 3
Yerry De los Santos 21.7 20.0 2

Players With Poor Balance
Player Rolling_CStr% Rolling_Chase% Days of Poor Performance
David Robertson 7.7 12.9 -16
Carlos Hernández 0.0 4.0 -2
Trey Yesavage 23.1 16.2 -1
Joe Rock 31.8 18.5 -1
Andrew Hoffmann 12.8 0.0 -2

The results focus on a pitcher’s most recent stretch. For example, Emilio Pagán has had one of his best K-BB% (22.4%) marks of his career this season, and in his last five games, it’s been even better (26.3%). He’s had recent success thanks to his four-seam and splitter working in unison.

Is there more to do? Always. I’ve only compared fastball called strike rates with offspeed chase rates, but all of these plate discipline metrics could be compared for balance. For example, it may be better to have a balanced swinging strike rate and chase rate. But, fundamental to this analysis is the assumption that it’s hard to get anywhere without a fastball and offspeed pitch that work well together. Does it mean anything? Is the balance even predictive of future success? Maybe, maybe not. What it certainly can do, as I believe I’ve exemplified here, is explain a pitcher’s success or lack thereof. If you are interested in doing this analysis on your own without spending hours calling and pinging pybaseball’s API, you can view pitch-specific plate discipline metrics on our new and totally awesome Pitch-Type Splits Leaderboards. Stay balanced, stay cool.


Mining the News (9/26/25)


Eric Hartline-Imagn Images

Note: Teams out of the playoffs are starting to drop end-of-season reports. I’m going to be behind for a couple of weeks catching up.

American League

Athletics

Zack Gelof had surgery on his shoulder.

Athletics second baseman Zack Gelof had successful surgery on his left shoulder to address an injury sustained earlier last week, the team announced Wednesday.

Dr. Neal ElAttrache performed an anterior labral-capsule repair in Los Angeles to address instability after Gelof’s injury in Pittsburgh on Sept. 19.

Read the rest of this entry »


Starting Pitcher Chart – September 26th, 2025

Lexi Thompson-Imagn Images

The chart includes their performance for 2025, their opponent’s wOBA rank versus the pitcher’s handedness from this year so far, my general start/sit recommendation for 10-team, 12-team, and 15-team (or more) leagues, and then a note about them. Obviously, there are league sizes beyond those three so it’s essentially a shallow, medium, deep. If a pitcher only has an “x” in 15-team, it doesn’t mean there’s no potential use in 10s and 12s, but it’s a much riskier stream for those spots.

These are general recommendations, and your league situation will carry more weight whether you are protecting ratios or chasing counting numbers. This is for standard 5×5 roto leagues. The thresholds for H2H starts are generally lower, especially in points leagues so I thought there would be more valuable focusing on roto.

Hit me with any questions in the comments!

Read the rest of this entry »


Starting Pitcher Chart – September 25th, 2025

Shota Imanago throws a pitch from the mound, Spring Training 2025
Credit: Rick Scuteri-Imagn Images

The chart includes their performance for 2025, their opponent’s wOBA rank versus the pitcher’s handedness from this year so far, my general start/sit recommendation for 10-team, 12-team, and 15-team (or more) leagues, and then a note about them. Obviously, there are league sizes beyond those three so it’s essentially a shallow, medium, deep. If a pitcher only has an “x” in 15-team, it doesn’t mean there’s no potential use in 10s and 12s, but it’s a much riskier stream for those spots.

These are general recommendations, and your league situation will carry more weight whether you are protecting ratios or chasing counting numbers. This is for standard 5×5 roto leagues. The thresholds for H2H starts are generally lower, especially in points leagues so I thought there would be more valuable focusing on roto.

Hit me with any questions in the comments!

Ober in for Ryan, obviously not nearly as interested and consider him really just a Hail Mary option in a decent matchup

Read the rest of this entry »


Request for Help: 2025 Initial Closers


Joe Puetz-Imagn Images

Every year I report on how many closers made it through the season and how Saves get distributed (2024 report). I just need help verifying the following list is correct before writing the final report next week. Thanks.

2025 Initial Closers
Team Eventual First Closer Going into season Notes
Angels Kenley Jansen One Guy
Astros Josh Hader One Guy
Athletics Mason Miller One Guy
Blue Jays Jeff Hoffman One Guy
Braves Raisel Iglesias One Guy
Brewers Trevor Megill One Guy
Cardinals Ryan Helsley One Guy
Cubs Ryan Pressly One Guy
Diamondbacks Justin Martinez One Guy
Dodgers Tanner Scott One Guy
Giants Ryan Walker One Guy
Guardians Emmanuel Clase One Guy
Mariners Andres Munoz One Guy
Marlins Calvin Faucher Committee Possibly Anthony Bender
Mets Edwin Diaz One Guy
Nationals Kyle Finnegan One Guy
Orioles Felix Bautista One Guy
Padres Robert Suarez One Guy
Phillies Jordan Romano One Guy
Pirates David Bednar One Guy
Rangers Luke Jackson One Guy
Rays Pete Fairbanks One Guy
Red Sox Aroldis Chapman One Guy
Reds Emilio Pagán One Guy
Rockies Seth Halvorsen Committee Possibly Zach Agnos or Tyler Kinley
Royals Carlos Estevez One Guy
Tigers Tommy Kahnle Committee Possibly Brant Hurter
Twins Jhoan Duran One Guy
White Sox Brandon Eisert Committee Eisert got the team’s only April Save. Possibly Jordan Leasure or Steven Wilson
Yankees Devin Williams One Guy

Starting Pitcher Chart – September 24th, 2025

Katie Stratman-USA TODAY Sports

The chart includes their performance for 2025, their opponent’s wOBA rank versus the pitcher’s handedness from this year so far, my general start/sit recommendation for 10-team, 12-team, and 15-team (or more) leagues, and then a note about them. Obviously, there are league sizes beyond those three so it’s essentially a shallow, medium, deep. If a pitcher only has an “x” in 15-team, it doesn’t mean there’s no potential use in 10s and 12s, but it’s a much riskier stream for those spots.

These are general recommendations, and your league situation will carry more weight whether you are protecting ratios or chasing counting numbers. This is for standard 5×5 roto leagues. The thresholds for H2H starts are generally lower, especially in points leagues so I thought there would be more valuable focusing on roto.

Board tonight, comments in the morning! (Fixed that date error)

Read the rest of this entry »


Crowdsourcing: Hitters Who Played Through an Injury


Syndication: The Enquirer

Before the fantasy baseball season finishes and all the managers disappear for a few months, it’s time to collect some information. Every season, I report on the batters who played through a known injury (2025 Edition). I have collected a few players throughout the season, but I am asking if anyone knows of any more hitters with a link to the source. No gut feels here. Once I get the complete list, I’ll create the full report.

Thanks for your time.

Hitters Who Played Through a 2025 Injury
Name Injury with Link
Anthony Santander Shoulder
Brendan Donovan Foot
Bryan Reynolds Shoulder
Bryce Harper Wrist
Corey Seager Calf
Elly De La Cruz Quad
Ernie Clement Hand
Ezequiel Tovar Hip
Freddie Freeman Neck
Jacob Wilson Hand
Jake Fraley Shoulder
Jazz Chisholm Jr. Shoulder
Jordan Westburg Finger
Lane Thomas Foot
Lars Nootbaar Rib
Marcell Ozuna Hip
Miguel Andujar Quad
Mike Trout Knee
Nick Castellanos Knee
Nolan Arenado Finger
Paul Goldschmidt Knee
Rafael Devers Back
Spencer Steer Shoulder
Willi Castro Wrist
Willson Contreras Finger
Xander Bogaerts Shoulder
Yoan Moncada Knee
Anthony Volpe Labrum Tear

Starting Pitcher Chart – September 23rd, 2025

Credit: Lon Horwedel-Imagn Images

The chart includes their performance for 2025, their opponent’s wOBA rank versus the pitcher’s handedness from this year so far, my general start/sit recommendation for 10-team, 12-team, and 15-team (or more) leagues, and then a note about them. Obviously, there are league sizes beyond those three so it’s essentially a shallow, medium, deep. If a pitcher only has an “x” in 15-team, it doesn’t mean there’s no potential use in 10s and 12s, but it’s a much riskier stream for those spots.

These are general recommendations, and your league situation will carry more weight whether you are protecting ratios or chasing counting numbers. This is for standard 5×5 roto leagues. The thresholds for H2H starts are generally lower, especially in points leagues so I thought there would be more valuable focusing on roto.

Board tonight, comments in the morning!

  • Pleeeeease let Skubes be great today, my Tigers need it sooo badly!
  • Webb survived his 2x v. LAD w/1 up, 1 down and has closed the season w/a solid 3.00 ERA/1.25 WHIP in 10 starts (60 IP)
  • Ragans only went 3.7 in his return from the IL with 62 pitches… he should get more this time out (75-80) which should be enough to at least get 5 IP… that said, I overranked him and underranked Horton so just consider them flipped
  • Ohtani now has 5 IP in 2 of his L3 and he was still great in 3.7 IP at BAL in between the two 5 IP outings so I’m OK running him anywhere
  • Gav Williams now has a 2.48 ERA over his L19 starts, dating back to June 1st; the skills were wobbly early in the run with a 5% K-BB casting a shadow over his 3.05 ERA in first 8 starts, but over his L11 he’s up to a solid 16% K-BB
  • I didn’t give Pepiot enough consideration last night and ranked him based on his season not hist recent stretch… he sputtered after some time off and with the Rays fully out of it, they could keep limiting Pep this week so I slashed an “x” and I consider him just below Giolito now
  • Miller is a little scary for sure, but you can’t pass on a COL start outside of Coors with a competent pitcher
  • Oviedo does have 3 BB in each of his L4 outings so there’s blowup risk here if he does it again and someone finally takes advantage (just 8 ER despite 1.55 WHIP)
  • The 1-x guys are so scary in this final week… there’s real upside with all of them, but season-ending downside, too

Read the rest of this entry »


Justin Mason’s Baseball Chat – September 22, 2025

Here is today’s chat transcript:
Read the rest of this entry »