📰 Dev.to · YMori
Articles from Dev.to · YMori · 36 articles · Updated every 3 hours · View all reads
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Dev.to · YMori
6d ago
transform: translateY(0) Breaks position: fixed — A Hidden Trap in SPA Animations
Why translateY(0) and transform none are not the same, and how this CSS spec detail silently breaks every fixed overlay on your page.

Dev.to · YMori
2w ago
NPB 2021 Backtest: Could a Bayesian Model Predict Last-Place-to-Champion?
Testing if Bayesian ensemble predictions with individual foreign player projections could predict Yakult and Orix going from last place to champions in 2021.

Dev.to · YMori
2w ago
Adding Bayesian Ensemble + Monte Carlo to an NPB Prediction App
How adding Bayesian corrections and foreign player projections changed NPB team standings predictions — with accuracy data from 8 years of backtesting.

Dev.to · YMori
2w ago
Adding Bayesian Ensemble + Monte Carlo to an NPB Prediction System
Notes on adding a Stan Bayesian model to an NPB baseball prediction app — Monte Carlo team simulation, credible intervals in Streamlit, and foreign player proje

Dev.to · YMori
3w ago
Moving an NPB Prediction System to BigQuery — BQML and Cloud Run on the Free Tier
I migrated my Japanese baseball (NPB) prediction system to Google BigQuery, trained BQML models with SQL window functions, and deployed the API to Cloud Run — a

Dev.to · YMori
3w ago
Monitoring the Strait of Hormuz Blockade with Open AIS Data and a Raspberry Pi
Building a real-time maritime monitoring system that quantifies the impact of the 2026 Hormuz crisis using free AIS data, Python, and a Raspberry Pi 5.

Dev.to · YMori
1mo ago
I Built a WBC Quarterfinal Scouting App with MLB Statcast Data
A 5-tab Streamlit dashboard analyzing Japan vs Venezuela using pitch-by-pitch MLB Statcast data — no coaching tone, just numbers

Dev.to · YMori
1mo ago
Cross-Repo README Sync with GitHub Actions — Push vs Pull Pattern
How to automatically sync stats between GitHub repositories using GitHub Actions, HTML comment markers, and a pull-based architecture that avoids PAT permission

Dev.to · YMori
1mo ago
Optimizing Marcel Projection Weights for NPB — Grid Search + Bootstrap Validation
The conventional Marcel weights (5/4/3) used in npb-prediction aren't optimal for NPB. I ran a 720-combination grid search on 11 years of NPB data and found sta

Dev.to · YMori
1mo ago
Can Statcast Data Improve MLB Player Performance Predictions? — Beating Marcel with LightGBM
I tried to beat the Marcel projection system using MLB Statcast tracking data (exit velocity, barrel rate, Whiff%, Stuff+). Here's what happened: +12.1% improve

Dev.to · YMori
1mo ago
Did Adding Stadium Correction Improve My NPB Baseball Predictions? — A Full Backtest Comparison
I added park factor correction to my Marcel+Stan Bayesian NPB standings model. Win MAE didn't change — but here's why that's expected, and what actually improve

Dev.to · YMori
1mo ago
I Added Park Factor Correction to My NPB Bayesian Prediction Model — Backtest Validation & 2026 Forecast
How adding park factor (PF) correction to a Marcel+Stan Bayesian NPB standings simulation affected accuracy across 8 seasons (2018-2025), and the resulting 2026

Dev.to · YMori
1mo ago
I Calculated NPB Park Factors for 10 Years — Stadium Renovations Revealed
Analyzing 8,619 NPB games (2016–2025) to compute park factors for all 12 stadiums, with special focus on how renovation projects (HR terraces, new stadiums) dra

Dev.to · YMori
1mo ago
Did Bayesian Projection (Stan/Ridge) Predict the 2021 NPB Last-to-First Upsets?
A follow-up to my Marcel analysis: I applied a Bayesian model (Stan/Ridge correction using K%, BB%, BABIP) to the same 2021 Yakult and Orix question — and found

Dev.to · YMori
1mo ago
Park Factors, OAA, and Stuff+ in One Line of Python (savant-extras v0.3.2–v0.4.1)
savant-extras v0.4.2: removed OAA/Outfield Jump/Stuff+ (already in pybaseball). Park factors remain as the unique addition.

Dev.to · YMori
1mo ago
Beyond Marcel: Adding Bayesian Regression to NPB Baseball Predictions — A 15-Step Journey
How I tried to beat the Marcel projection system for NPB (Japanese pro baseball) using Stan/Ridge regression with K%/BB%/BABIP features, and what I learned abou

Dev.to · YMori
1mo ago
Does Exit Velocity Come from the Front Foot? Exploring Driveline Motion Capture Data
I analyzed 40 hitters using Driveline OpenBiomechanics C3D data and found that front leg mechanics — not bat speed — may be the key differentiator in exit veloc

Dev.to · YMori
1mo ago
Last Place to Champions: What Marcel Projection Reveals About 2021 NPB Yakult and Orix
In 2021, both pennant winners came from last place the year before. Using Marcel team projections with roster-verified data, I analyzed why — and found a league

Dev.to · YMori
1mo ago
Why Two Pitchers with the Same Arm Speed Differ by 10 mph — A Motion Capture Analysis
I analyzed 61 pro pitchers using Driveline OpenBiomechanics C3D data and found 5 body mechanics factors that explain a 10+ mph gap in pitch speed among pitchers

Dev.to · YMori
1mo ago
Annual Auto-Retraining for NPB Baseball Predictions with GitHub Actions
I added CI/CD to my NPB player performance prediction system: joblib model artifacts, annual metrics JSON, a FastAPI /metrics endpoint, and an 8-step GitHub Act

Dev.to · YMori
1mo ago
HTTP 200 but Your Streamlit App Is Still Sleeping — Why GET Requests Don't Work and How Playwright Fixes It
Streamlit Community Cloud apps sleep after inactivity. HTTP GET returns 200 with a static HTML shell, but the Python app never starts. Use Playwright to actuall

Dev.to · YMori
1mo ago
3D Skeleton Detection from Baseball Motion Capture Data with Driveline C3D
I analyzed pitching and hitting biomechanics using Driveline OpenBiomechanics C3D data, ezc3d, and MediaPipe. Trunk rotation range showed the strongest correlat

Dev.to · YMori
1mo ago
Why Marcel Beat LightGBM: Building an NPB Player Performance Prediction System
I built a Japanese professional baseball (NPB) player performance prediction system using Marcel projection, LightGBM/XGBoost, custom wOBA/wRC+ calculation, and

Dev.to · YMori
1mo ago
I Built a Python Package for Every Baseball Savant Leaderboard
savant-extras now covers 16 Baseball Savant leaderboards that pybaseball doesn't support — Pitch Movement, Catcher Blocking, Basestealing, Timer Infractions, an
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