dnevBaseball
@dnevbaseball.bsky.social
Baseball fan who also likes numbers. ⚾📊
Check out my Swing Decision metrics apps:
(MLB) https://dnev-baseball.shinyapps.io/Swing_Decisions/
(Winter Leagues) https://dnev-baseball.shinyapps.io/Swing_Decisions_Winter/
https://medium.com/@dnevBaseball
Check out my Swing Decision metrics apps:
(MLB) https://dnev-baseball.shinyapps.io/Swing_Decisions/
(Winter Leagues) https://dnev-baseball.shinyapps.io/Swing_Decisions_Winter/
https://medium.com/@dnevBaseball
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dnevBaseball
@dnevbaseball.bsky.social
· Jan 15
dnevBaseball – Medium
Read writing from dnevBaseball on Medium. Every day, dnevBaseball and thousands of other voices read, write, and share important stories on Medium.
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I created a metric called Swing Decision Runs (SDr) to measure the run value of a swing decision above average for each pitch.
An explanation of how the metric is calculated can be found here:
medium.com/@dnevBaseball
An explanation of how the metric is calculated can be found here:
medium.com/@dnevBaseball
Thinking about switching from the box and whisker plots I've been using to a more condensed dashboard with percentiles and the deserved wOBA based on these metrics. Would probably keep the plots for year-to-year comparisons, though. Any feedback would be appreciated!
January 8, 2026 at 10:07 PM
Thinking about switching from the box and whisker plots I've been using to a more condensed dashboard with percentiles and the deserved wOBA based on these metrics. Would probably keep the plots for year-to-year comparisons, though. Any feedback would be appreciated!
Despite bad numbers in 2025, Austin Slater might deserve one last look if a team is need of a righty platoon bat. The results weren't pretty, but the underlying metrics suggest some bad luck. Especially when looking at Impact 👀 Biggest concern is the increase in chase rate.
January 6, 2026 at 7:07 PM
Despite bad numbers in 2025, Austin Slater might deserve one last look if a team is need of a righty platoon bat. The results weren't pretty, but the underlying metrics suggest some bad luck. Especially when looking at Impact 👀 Biggest concern is the increase in chase rate.
Looking forward to seeing Sal Stewart in a full season. He showed plenty of power in his 58 PAs in 2025. Along with adequate contact skills and swing decisions.
January 3, 2026 at 7:06 PM
Looking forward to seeing Sal Stewart in a full season. He showed plenty of power in his 58 PAs in 2025. Along with adequate contact skills and swing decisions.
Reposted by dnevBaseball
Hi, BlueSky converts. Probably deserves some updating, but here's a list of baseball analytics nerds if that's up your alley.
go.bsky.app/GZjLuxK
go.bsky.app/GZjLuxK
January 2, 2026 at 8:28 PM
Hi, BlueSky converts. Probably deserves some updating, but here's a list of baseball analytics nerds if that's up your alley.
go.bsky.app/GZjLuxK
go.bsky.app/GZjLuxK
Jahmai Jones slashed .287/.387/.550 in a platoon role over a career high 150 PAs in 2025. His dwOBA suggests he was a bit lucky, but he showed major improvement in swing decisions and Impact.
December 30, 2025 at 6:04 PM
Jahmai Jones slashed .287/.387/.550 in a platoon role over a career high 150 PAs in 2025. His dwOBA suggests he was a bit lucky, but he showed major improvement in swing decisions and Impact.
Using my new regression model, I determined a deserved wOBA (dwOBA) based on their SDr, Connect, and Impact. The graph is a probability distribution of the dwOBA with the most likely value labeled. The hitter's actual wOBA is also shown for comparison.
December 30, 2025 at 4:41 AM
Using my new regression model, I determined a deserved wOBA (dwOBA) based on their SDr, Connect, and Impact. The graph is a probability distribution of the dwOBA with the most likely value labeled. The hitter's actual wOBA is also shown for comparison.
Here are the plots to go with the Importance Index determined from a couple days ago. I thought there might be a steep drop off if Contact got too bad (indicating there was some minimum level of contact ability required), but the results don't show much of one.
December 27, 2025 at 3:54 AM
Here are the plots to go with the Importance Index determined from a couple days ago. I thought there might be a steep drop off if Contact got too bad (indicating there was some minimum level of contact ability required), but the results don't show much of one.
I've been playing around with developing a non-linear Bayesian regression model to predict wOBA from SDr, Connect+, and Impact+. I'd like to determine the contribution from each to wOBA. My first attempt came up with Impact+ at ~50%, Connect+ at ~30%, and SDr at ~20%. This seems about right?
December 24, 2025 at 4:36 AM
I've been playing around with developing a non-linear Bayesian regression model to predict wOBA from SDr, Connect+, and Impact+. I'd like to determine the contribution from each to wOBA. My first attempt came up with Impact+ at ~50%, Connect+ at ~30%, and SDr at ~20%. This seems about right?
Willson Contreras makes up for below average Connect+ with adequate swing decisions and excellent Impact+. The drop in walk rate in 2025 looks to be due to pitchers throwing in the zone to him more often.
December 22, 2025 at 4:04 AM
Willson Contreras makes up for below average Connect+ with adequate swing decisions and excellent Impact+. The drop in walk rate in 2025 looks to be due to pitchers throwing in the zone to him more often.
Jhonkensy Noel's 2025 was rough, but not sure I would give up on him so soon after the power he showed in 2024.
December 18, 2025 at 3:40 AM
Jhonkensy Noel's 2025 was rough, but not sure I would give up on him so soon after the power he showed in 2024.
Maikel Garcia's offensive 2025 breakout came due to increasing his already excellent contact rate, slightly increasing his contact quality, and maintaining his good swing decisions (mainly by not swinging a lot). Also, an increased Pull Air% also helps!
December 15, 2025 at 6:41 PM
Maikel Garcia's offensive 2025 breakout came due to increasing his already excellent contact rate, slightly increasing his contact quality, and maintaining his good swing decisions (mainly by not swinging a lot). Also, an increased Pull Air% also helps!
Coby Mayo and Ryan Mountcastle are probably most affected in Baltimore by the Alonso signing.
Mayo needs to improve his contact if he's not going to hit for more power.
Mountcastle's contact rate really stepped back in 2025, and he saw a dip in BB% and K%.
Mayo needs to improve his contact if he's not going to hit for more power.
Mountcastle's contact rate really stepped back in 2025, and he saw a dip in BB% and K%.
December 15, 2025 at 3:28 AM
Coby Mayo and Ryan Mountcastle are probably most affected in Baltimore by the Alonso signing.
Mayo needs to improve his contact if he's not going to hit for more power.
Mountcastle's contact rate really stepped back in 2025, and he saw a dip in BB% and K%.
Mayo needs to improve his contact if he's not going to hit for more power.
Mountcastle's contact rate really stepped back in 2025, and he saw a dip in BB% and K%.
Last is the Impact+ stability curve. Impact+ is reliable after ~130 balls in play.
December 2, 2025 at 8:45 PM
Last is the Impact+ stability curve. Impact+ is reliable after ~130 balls in play.
Ran the stability analysis on Connect+ and found it to be reliable in about 120 swings. At about 2 swings per plate appearance (~4 pitches per average PA and a 50% swing rate), the metric stabilizes in 60 PAs. This is slightly less than SDr, which was ~100 PAs.
December 2, 2025 at 3:32 PM
Ran the stability analysis on Connect+ and found it to be reliable in about 120 swings. At about 2 swings per plate appearance (~4 pitches per average PA and a 50% swing rate), the metric stabilizes in 60 PAs. This is slightly less than SDr, which was ~100 PAs.
Finally got around to making a stability curve for Swing Decision Runs! SDr becomes stable at around 400 pitches.
medium.com/@dnevBasebal...
medium.com/@dnevBasebal...
November 30, 2025 at 4:25 AM
Finally got around to making a stability curve for Swing Decision Runs! SDr becomes stable at around 400 pitches.
medium.com/@dnevBasebal...
medium.com/@dnevBasebal...
Brandon Nimmo's 2025 looked similar to 2024. A drop in walk rate from 11.6% to 7.7% was almost entirely due to an sharp increase in Zone%. I'll be interested to see if he sees a similar Zone% in Texas next year.
November 25, 2025 at 4:25 AM
Brandon Nimmo's 2025 looked similar to 2024. A drop in walk rate from 11.6% to 7.7% was almost entirely due to an sharp increase in Zone%. I'll be interested to see if he sees a similar Zone% in Texas next year.
Marcus Semien's contact ability took a step back in 2025, and it showed in his K% which jumped from 14.6% to 17.4%.
November 25, 2025 at 4:20 AM
Marcus Semien's contact ability took a step back in 2025, and it showed in his K% which jumped from 14.6% to 17.4%.
Yainer has the contact skills and contact quality to be an impact bat, but the swing decisions really weigh him down. A hitter this good at making contact doesn't need to swinging so much.
November 23, 2025 at 4:21 AM
Yainer has the contact skills and contact quality to be an impact bat, but the swing decisions really weigh him down. A hitter this good at making contact doesn't need to swinging so much.
Naylor mixes elite contact with above average contact quality. His contact skills allow him to post below average K-rates even with suboptimal swing decisions.
Need to look further, but I'd think his Impact+ is well above the expected value for hitters with his contact ability.
Need to look further, but I'd think his Impact+ is well above the expected value for hitters with his contact ability.
November 18, 2025 at 8:56 PM
Naylor mixes elite contact with above average contact quality. His contact skills allow him to post below average K-rates even with suboptimal swing decisions.
Need to look further, but I'd think his Impact+ is well above the expected value for hitters with his contact ability.
Need to look further, but I'd think his Impact+ is well above the expected value for hitters with his contact ability.
Which of these potential Angels outfielders do you prefer as a trade target, Jo Adell or Taylor Ward?
November 10, 2025 at 10:48 PM
Which of these potential Angels outfielders do you prefer as a trade target, Jo Adell or Taylor Ward?
Created a new Shiny app with Arizona Fall League plate discipline stats. I hope to keep adding to this with other winter leagues.
dnev-baseball.shinyapps.io/Swing_Decisi...
dnev-baseball.shinyapps.io/Swing_Decisi...
AFL Plate Discipline
dnev-baseball.shinyapps.io
November 8, 2025 at 4:17 AM
Created a new Shiny app with Arizona Fall League plate discipline stats. I hope to keep adding to this with other winter leagues.
dnev-baseball.shinyapps.io/Swing_Decisi...
dnev-baseball.shinyapps.io/Swing_Decisi...
Not much change in plate discipline / hitting approach for the Dodgers or Blue Jays during the World Series compared to the regular season. Chase rates up a bit (to be expected against better pitching). Blue Jays still good at making contact outside the strike zone.
November 3, 2025 at 3:56 AM
Not much change in plate discipline / hitting approach for the Dodgers or Blue Jays during the World Series compared to the regular season. Chase rates up a bit (to be expected against better pitching). Blue Jays still good at making contact outside the strike zone.
These are totals, so the extra pitches help, but the Blue Jays have been far and away the best at making contact in the playoffs.
October 30, 2025 at 9:12 PM
These are totals, so the extra pitches help, but the Blue Jays have been far and away the best at making contact in the playoffs.
2025 Swing Decision Runs leaders:
September 30, 2025 at 7:25 PM
2025 Swing Decision Runs leaders:
There was almost a repeat from 2024 to 2025 for the player with the highest Swing Decision Runs per pitch (min 1000 pitches). The top hitter in 2024 finished second this year.
Lowest SDr was a repeat.
Anyone want to take a guess who the hitters are? Bonus points if you get 2025's leader!
Lowest SDr was a repeat.
Anyone want to take a guess who the hitters are? Bonus points if you get 2025's leader!
September 29, 2025 at 8:33 PM
There was almost a repeat from 2024 to 2025 for the player with the highest Swing Decision Runs per pitch (min 1000 pitches). The top hitter in 2024 finished second this year.
Lowest SDr was a repeat.
Anyone want to take a guess who the hitters are? Bonus points if you get 2025's leader!
Lowest SDr was a repeat.
Anyone want to take a guess who the hitters are? Bonus points if you get 2025's leader!