Stephen Sutton-Brown
@srbrown70.bsky.social
Braves, heat maps, cars, tractors, and music
Creator of StuffPro and Arsenal Metrics at Baseball Prospectus
He / him
Creator of StuffPro and Arsenal Metrics at Baseball Prospectus
He / him
Pinned
Introducing BP's new Arsenal Metrics | Baseball Prospectus
A new way at quantifying not just individual pitches, but how they work together.
www.baseballprospectus.com
I have never been more excited to release an article: Introducing BPro’s new Arsenal Metrics! www.baseballprospectus.com/news/article...
*quietly evaluating my nephew's hot wheels collection for potential trade candidates*
November 26, 2025 at 10:38 PM
*quietly evaluating my nephew's hot wheels collection for potential trade candidates*
Sonny Gray is 8th in Pitch Type Probability and 13th in Movement Spread, but he's 61st in Velocity Spread and 43rd in Surprise Factor. His Tunnel Pair for every pitch is the SW, whose Tunnel Pair is the four-seam. It feels unique but it works, & it's someone I've wanted the Braves to get for a while
November 26, 2025 at 2:49 AM
Sonny Gray is 8th in Pitch Type Probability and 13th in Movement Spread, but he's 61st in Velocity Spread and 43rd in Surprise Factor. His Tunnel Pair for every pitch is the SW, whose Tunnel Pair is the four-seam. It feels unique but it works, & it's someone I've wanted the Braves to get for a while
good nuggets here
blogs.fangraphs.com/a-late-seaso...
blogs.fangraphs.com/a-late-seaso...
November 26, 2025 at 2:10 AM
good nuggets here
blogs.fangraphs.com/a-late-seaso...
blogs.fangraphs.com/a-late-seaso...
I can see the pearly gates
Where the angels wait
Standin' all around your big Cadillac
Won't you take me by the hand
Lead me to the promised land
And let me ride in your big Cadillac
Let me ride in your big Cadillac, Lord Jesus
Let me ride in your big Cadillac
Where the angels wait
Standin' all around your big Cadillac
Won't you take me by the hand
Lead me to the promised land
And let me ride in your big Cadillac
Let me ride in your big Cadillac, Lord Jesus
Let me ride in your big Cadillac
November 23, 2025 at 5:37 PM
I can see the pearly gates
Where the angels wait
Standin' all around your big Cadillac
Won't you take me by the hand
Lead me to the promised land
And let me ride in your big Cadillac
Let me ride in your big Cadillac, Lord Jesus
Let me ride in your big Cadillac
Where the angels wait
Standin' all around your big Cadillac
Won't you take me by the hand
Lead me to the promised land
And let me ride in your big Cadillac
Let me ride in your big Cadillac, Lord Jesus
Let me ride in your big Cadillac
Reposted by Stephen Sutton-Brown
not a good sign
November 22, 2025 at 4:58 PM
not a good sign
not a good sign
November 22, 2025 at 4:58 PM
not a good sign
saving this for future uses
November 22, 2025 at 1:49 AM
saving this for future uses
For their learning bag they were told to bring in a picture of “their favorite spot in the community” and they insisted on pictures of Taco Bell lmao
November 21, 2025 at 3:43 PM
For their learning bag they were told to bring in a picture of “their favorite spot in the community” and they insisted on pictures of Taco Bell lmao
Made a simulator using a simplified version of a pitching model so I can start testing various pitching strategies (changing pitch usage rates by game state, targeting further outside the zone in certain situations, etc.).
Simulated results match reality pretty well!
Simulated results match reality pretty well!
November 21, 2025 at 3:15 PM
Made a simulator using a simplified version of a pitching model so I can start testing various pitching strategies (changing pitch usage rates by game state, targeting further outside the zone in certain situations, etc.).
Simulated results match reality pretty well!
Simulated results match reality pretty well!
Reposted by Stephen Sutton-Brown
The New October Blueprint: Lean on Your Best, Not Your Bullpen
by Joshua Rodrigues (@jrodrigues39.bsky.social)
www.baseballprospectus.com/news/article...
by Joshua Rodrigues (@jrodrigues39.bsky.social)
www.baseballprospectus.com/news/article...
The New October Blueprint: Lean on Your Best, Not Your Bullpen | Baseball Prospectus
Starters are back.
www.baseballprospectus.com
November 19, 2025 at 7:15 PM
The New October Blueprint: Lean on Your Best, Not Your Bullpen
by Joshua Rodrigues (@jrodrigues39.bsky.social)
www.baseballprospectus.com/news/article...
by Joshua Rodrigues (@jrodrigues39.bsky.social)
www.baseballprospectus.com/news/article...
Some rules of thumb for the Arsenal Metrics by pitch type:
November 19, 2025 at 2:24 PM
Some rules of thumb for the Arsenal Metrics by pitch type:
Reposted by Stephen Sutton-Brown
Further reminder that nominating your own work is not just allowed but encouraged. If you wrote something you’re proud of, make sure to nominate it!
Hey, SABR hasn't put both its feet into bluesky yet (I know, a lot of its people have) but this is a good time to remind you that the SABR Analytics Conference Research Awards are open for nominations.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
Seeking nominations for 2026 SABR Analytics Conference Research Awards – Society for American Baseball Research
sabr.org
November 18, 2025 at 2:28 AM
Further reminder that nominating your own work is not just allowed but encouraged. If you wrote something you’re proud of, make sure to nominate it!
Reposted by Stephen Sutton-Brown
Hey, SABR hasn't put both its feet into bluesky yet (I know, a lot of its people have) but this is a good time to remind you that the SABR Analytics Conference Research Awards are open for nominations.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
Seeking nominations for 2026 SABR Analytics Conference Research Awards – Society for American Baseball Research
sabr.org
November 17, 2025 at 7:54 PM
Hey, SABR hasn't put both its feet into bluesky yet (I know, a lot of its people have) but this is a good time to remind you that the SABR Analytics Conference Research Awards are open for nominations.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
When you have a few minutes, please nominate some of your favorite baseball research from 2025.
If I'm understanding players right when they talk about this, I think this illustrates risks with an approach that looks to pull everything. First plot is sweep of Ohtani's barrel if he swings to target the fastball middle and at the front of the plate. Second is away and deep.
November 16, 2025 at 3:20 AM
If I'm understanding players right when they talk about this, I think this illustrates risks with an approach that looks to pull everything. First plot is sweep of Ohtani's barrel if he swings to target the fastball middle and at the front of the plate. Second is away and deep.
Reposted by Stephen Sutton-Brown
Here are two swings, same hitter, overlaid on each other, one makes contact with a ball in Zone 10, the other, Zone 11 (up+out vs up+in)
Barrels (red/purple) tunnel each other like 2 pitches tunnelling each other. But from overhead view you can see that they break off pretty early in the motion
Barrels (red/purple) tunnel each other like 2 pitches tunnelling each other. But from overhead view you can see that they break off pretty early in the motion
November 15, 2025 at 5:02 PM
Here are two swings, same hitter, overlaid on each other, one makes contact with a ball in Zone 10, the other, Zone 11 (up+out vs up+in)
Barrels (red/purple) tunnel each other like 2 pitches tunnelling each other. But from overhead view you can see that they break off pretty early in the motion
Barrels (red/purple) tunnel each other like 2 pitches tunnelling each other. But from overhead view you can see that they break off pretty early in the motion
The thing about putting in the effort to make that streamlit app is this exists, which will show much of the same info just doesn't include a good way to visualize the time domain.
baseballsavant.mlb.com/leaderboard/...
baseballsavant.mlb.com/leaderboard/...
November 15, 2025 at 7:39 PM
The thing about putting in the effort to make that streamlit app is this exists, which will show much of the same info just doesn't include a good way to visualize the time domain.
baseballsavant.mlb.com/leaderboard/...
baseballsavant.mlb.com/leaderboard/...
Decided to make the code for generating these plots public. Download the stuff here to run it in a jupyter notebook. You can input any batter from 2025. Count options are "other", "full", "batter_ahead", and "two_strikes"
github.com/sbrown70/bar...
github.com/sbrown70/bar...
November 15, 2025 at 7:33 PM
Decided to make the code for generating these plots public. Download the stuff here to run it in a jupyter notebook. You can input any batter from 2025. Count options are "other", "full", "batter_ahead", and "two_strikes"
github.com/sbrown70/bar...
github.com/sbrown70/bar...
Got lots of leaves to rake tomorrow so plenty of time to ponder how to interpret this stuff. Just think there's more info in here to understand how and why batters are adjusting to a pitch if we can figure out how to look
November 14, 2025 at 3:30 AM
Got lots of leaves to rake tomorrow so plenty of time to ponder how to interpret this stuff. Just think there's more info in here to understand how and why batters are adjusting to a pitch if we can figure out how to look
Ok well lets start by fixing the slope of attack direction as a function of intercept point, that gives us a pretty different takeaway.
November 14, 2025 at 2:40 AM
Ok well lets start by fixing the slope of attack direction as a function of intercept point, that gives us a pretty different takeaway.
Today's bat path work.
November 14, 2025 at 2:01 AM
Today's bat path work.
Same data but in plot form for 0-0 counts after fitting a GAM on Percentage of Predicted Bat Speed for each of the y variables. Red lines are GAM fit on league data weighted by number of swings at that percentage, gray lines are individual unweighted GAMs for 100 random batters.
November 12, 2025 at 6:46 PM
Same data but in plot form for 0-0 counts after fitting a GAM on Percentage of Predicted Bat Speed for each of the y variables. Red lines are GAM fit on league data weighted by number of swings at that percentage, gray lines are individual unweighted GAMs for 100 random batters.
The additional whiffs that come from swinging hard appear to be worth the increase in hard contact, but it's tough to tell if that's an artifact of hard swings disproportionately being swings where the batter correctly guessed pitch type.
November 12, 2025 at 4:16 PM
The additional whiffs that come from swinging hard appear to be worth the increase in hard contact, but it's tough to tell if that's an artifact of hard swings disproportionately being swings where the batter correctly guessed pitch type.
this is horribly unimaginative
www.caranddriver.com/photos/g6934...
www.caranddriver.com/photos/g6934...
November 11, 2025 at 8:11 PM
this is horribly unimaginative
www.caranddriver.com/photos/g6934...
www.caranddriver.com/photos/g6934...
