--- pretty_name: MLB Shared Stats tags: - baseball - mlb - statcast - sabermetrics language: - en configs: - config_name: catcher data_files: catcher.parquet - config_name: fg_batting data_files: fg_batting.parquet - config_name: fg_pitcher_plus data_files: fg_pitcher_plus.parquet - config_name: fg_pitching data_files: fg_pitching.parquet - config_name: oaa data_files: oaa.parquet - config_name: oaa_team data_files: oaa_team.parquet - config_name: park_factors data_files: park_factors.parquet - config_name: sc_bat_tracking data_files: sc_bat_tracking.parquet - config_name: sc_batted_ball data_files: sc_batted_ball.parquet - config_name: sc_batter_exitvelo data_files: sc_batter_exitvelo.parquet - config_name: sc_batter_expected data_files: sc_batter_expected.parquet - config_name: sc_pitcher_arsenal data_files: sc_pitcher_arsenal.parquet - config_name: sc_pitcher_exitvelo data_files: sc_pitcher_exitvelo.parquet - config_name: sc_pitcher_expected data_files: sc_pitcher_expected.parquet - config_name: sprint_speed data_files: sprint_speed.parquet - config_name: statsapi_batting data_files: statsapi_batting.parquet - config_name: statsapi_pitching data_files: statsapi_pitching.parquet - config_name: mart_batter_season data_files: marts/mart_batter_season.parquet - config_name: mart_pitcher_season data_files: marts/mart_pitcher_season.parquet - config_name: mart_batter_aging_pairs data_files: marts/mart_batter_aging_pairs.parquet - config_name: mart_pitch_arsenal_scouting data_files: marts/mart_pitch_arsenal_scouting.parquet - config_name: mart_scouting_reliability data_files: marts/mart_scouting_reliability.parquet - config_name: mart_batter_process_reliability data_files: marts/mart_batter_process_reliability.parquet - config_name: mart_pitcher_process_reliability data_files: marts/mart_pitcher_process_reliability.parquet - config_name: mart_fielding_running_reliability data_files: marts/mart_fielding_running_reliability.parquet --- # MLB Shared Stats Season-level MLB tables, refreshed weekly by [yasumorishima/mlb-data-pipeline](https://github.com/yasumorishima/mlb-data-pipeline) and published here as Parquet. One file per table at the repository root. **Read the freshness column before using a table.** Not everything here is current, and the rows in a stale table look exactly like the rows in a fresh one. ## Tables | File | Source | Seasons | Refreshed | |---|---|---|---| | `sc_batter_exitvelo.parquet` | Baseball Savant | 2015– | weekly | | `sc_pitcher_exitvelo.parquet` | Baseball Savant | 2015– | weekly | | `sc_batter_expected.parquet` | Baseball Savant | 2015– | weekly | | `sc_pitcher_expected.parquet` | Baseball Savant | 2015– | weekly | | `sc_pitcher_arsenal.parquet` | Baseball Savant | 2017– | weekly | | `sc_batted_ball.parquet` | Baseball Savant | 2015– | weekly | | `sc_bat_tracking.parquet` | Baseball Savant | 2024– (Hawk-Eye) | weekly | | `sprint_speed.parquet` | Baseball Savant | 2015– | weekly | | `oaa.parquet` | Baseball Savant | 2016– | weekly | | `oaa_team.parquet` | Baseball Savant | 2016– | weekly | | `catcher.parquet` | Baseball Savant | 2015– | weekly | | `park_factors.parquet` | Baseball Savant | 2015– | weekly (added 2026-09-23) | | `statsapi_batting.parquet` | MLB Stats API | 2015– | weekly (added 2026-09-23) | | `statsapi_pitching.parquet` | MLB Stats API | 2015– | weekly (added 2026-09-23) | | `fg_batting.parquet` | FanGraphs | 2015–**2025** | ⚠️ **frozen 2026-04** | | `fg_pitching.parquet` | FanGraphs | 2015–**2025** | ⚠️ **frozen 2026-04** | | `fg_pitcher_plus.parquet` | FanGraphs | 2020–**2025** | ⚠️ **frozen 2026-04** | `statcast_pitches` (pitch-level, ~6.8M rows) is fetched by manual dispatch only and is not part of the weekly refresh. ## Marts (`marts/`) Analysis-ready tables built from the tables above by the [dbt project](https://github.com/yasumorishima/mlb-data-pipeline/tree/master/dbt) and republished after every weekly refresh, only when all of its data tests pass. A build that fails leaves the previous marts in place, so they can lag the raw tables: `marts/_manifest.json` records when they were built, the pipeline commit, and the revision of this dataset they were built from. Rows for a season whose regular season is not over carry `is_partial = true`. | File | Grain | |---|---| | `marts/mart_batter_season.parquet` | batter-season (PA > 0): wOBA, wRC+, WAR next to xwOBA, batted-ball mix, bat speed, sprint speed, OAA | | `marts/mart_pitcher_season.parquet` | pitcher-season: K%, BB%, K-BB%, FIP, xERA, pitch-mix breadth | | `marts/mart_batter_aging_pairs.parquet` | same batter, season and season + 1: input for aging curves | | `marts/mart_pitch_arsenal_scouting.parquet` | pitcher-season-pitch: usage rank, whiff and run-value percentiles within type | | `marts/mart_scouting_reliability.parquet` | metric x sample-size bin: year-to-year correlation of each pitch metric, raw and within pitch type | | `marts/mart_batter_process_reliability.parquet` | metric x PA bin: year-to-year correlation of each batting number and its correlation with next season's wOBA | | `marts/mart_pitcher_process_reliability.parquet` | metric x BF bin: year-to-year correlation of each pitching number and its correlation with next season's ERA | | `marts/mart_fielding_running_reliability.parquet` | metric x position or competitive-run bin: year-to-year correlation of OAA, fielding runs prevented, catch rate above expected, sprint speed and home to first | ### Why the three FanGraphs tables are frozen FanGraphs refuses the GitHub Actions runner. The cause is the **address**, not the client: pybaseball sets no `User-Agent`, so it sends the honest `python-requests` default, and it still got HTTP 403 for all 12 seasons on [run 35565978836](https://github.com/yasumorishima/mlb-data-pipeline/actions/runs/35565978836) (2026-09-21). The same request from a home connection returns 200. There is a second, separate layer that is easy to confuse with it: a client claiming to be a browser gets 403 with `cf-mitigated: challenge` from *anywhere*, including a residential line. Measured 2026-09-23. So these three tables hold a rescue snapshot taken in 2026-04, which ends with the 2025 season. **They contain no 2026 rows.** The pipeline reports them on every run and the exemption has an expiry date, so this cannot quietly become permanent. For current wOBA / wRC+ / WAR / FIP / xFIP, use `statsapi_batting` and `statsapi_pitching` below. They are **not** FanGraphs tables. ## `statsapi_batting` / `statsapi_pitching` From the [MLB Stats API](https://statsapi.mlb.com/api/v1/stats), keyless: `stats=season` (counting and rate stats) joined with `stats=sabermetrics` (wOBA, wRAA, wRC, wRC+, WAR and its components for hitters; FIP, xFIP, FIP-, ERA-, WAR, RA9-WAR, leverage for pitchers), `playerPool=ALL`. Column names are the API's own (`plateAppearances`, `wRcPlus`, `xfip`, …). Responses carry "Copyright MLB Advanced Media, L.P." and point to the terms at . **MLB does not document how its sabermetrics feed is computed or where it comes from.** What we measured, 2026-09-23, joining on MLBAM `player_id` against the frozen FanGraphs snapshot above (every one of its 5,703 hitter and 4,648 pitcher rows matched): - Counting stats agree exactly (HR, SO; PA within 1). - 2015–2021: wOBA within 0.002, wRC+ within 0.5 (FanGraphs stores integers), WAR within 0.2, FIP / xFIP within 0.005 — i.e. rounding. - 2022–2025: wOBA still within 0.006, but wRC+ differs by up to 1.0 (2022, 2023), 3.4 (2024) and 5.6 (2025), and the 2025 difference is lined up by club (ATH +5.1, CIN −3.1). Park factors were revised after the snapshot. WAR follows: up to 0.34 for hitters in 2024, and 0.39 for hitters and 0.40 for pitchers in 2025. One 2024 pitcher differs by 0.31 in FIP and 0.32 in xFIP; the other 433 by ≤ 0.005. So **past seasons can change from one week to the next**; every run refetches every season. Rows and columns: - One row per `(player_id, season)`, every player who appeared, not a qualified subset (e.g. 1,252 hitters in 2015 against 546 in the FanGraphs snapshot). The hitter count falls from ~1,250 to ~770 in 2022 because the universal DH ended pitchers batting. - A player who changed clubs has **one row with his season total**. `last_team_id` is the club he finished with and `num_teams` how many he played for. It is not "his stats for that club". - `is_partial` is true for the current season until every regular-season game is final. `fetched_at` is when the row was read. - `inningsPitched` is kept as the API's string: `"5.1"` means five and one third innings, not 5.1. Use `outs / 3`. - Rates are absent where the denominator is zero: `woba` / `wRcPlus` for hitters with 0 PA (288 of 1,252 in 2015), `fip` / `xfip` for a pitcher with 0 outs. Placeholder strings such as `".---"` become null. - In the current season a pitcher can appear in `stats=season` before `stats=sabermetrics` (one in 2026); his sabermetric columns are null. The fetch fails and these two tables are not published if a response was truncated (`totalSplits` ≠ rows returned), answered for another season, lacks a required stat, repeats a player, has a player only the sabermetrics side knows, or if a completed season now has fewer players than the copy already published here. A run that checked the ids and knows MLB removed a player (e.g. merged a duplicate id) can publish with the `allow_statsapi_shrink` workflow input. For every table except `statcast_pitches` (one file per season, so a narrower run cannot remove the others), the output audit also refuses to publish a file that lacks a season the published copy has, so a manual run over a narrower year range cannot delete seasons from here. A deliberate removal has to name the table in the `allow_lost_seasons` workflow input. The weekly run covers seasons up to the latest one in which every club has played a game, read from the Stats API standings; before that (and through an overseas opening series) it stops at the previous season. ### Why you can trust the "weekly" column Every run audits what it produced. A table that fetched nothing used to be skipped silently — the upload step pushes whatever files exist, so the copy here simply stayed as it was and the job still went green. That is how `park_factors` never arrived at all until 2026-09-23, and how the FanGraphs tables went stale without an alarm. Now `scripts/check_outputs.py` prints one row per expected table, publishes only the tables that passed, and turns the run red otherwise. ## `park_factors` columns One row per club per season, all 30 clubs in every season. 100 = neutral, above 100 favours hitters. From Baseball Savant's Statcast park factors. `season`, `team`, `venue_id`, `venue_name`, `n_pa_1yr`, `n_pa_3yr`, `pf_1yr`, `pf_3yr`, `pf_3yr_years`, then `pf_hr`, `pf_1b`, `pf_2b`, `pf_3b`, `pf_so`, `pf_bb`, `pf_obp`, `pf_hits`, `pf_woba`, `pf_wobacon`, `pf_xwobacon`, `pf_bacon`, `pf_xbacon`, `pf_hardhit`, `pf_wobatto`. Everything except `pf_1yr` and `n_pa_1yr` comes from a 3-year window; `pf_3yr_years` records which window that was. Two NaN patterns are expected, not defects: - **8 rows of 360 have no 3-year window at all**, because the park has no three-year history: 2017 ATL, 2018 ATL, 2020 TEX, 2020 TOR, 2021 TEX, 2025 OAK, 2025 TB, 2026 OAK. Their `pf_3yr*` columns are NaN while `pf_1yr` is filled. The club is kept rather than dropped, so a team never silently disappears from a season. - **`pf_xwobacon`, `pf_xbacon` and `pf_hardhit` are NaN for all 30 clubs in 2015 and 2016**, because those windows reach back before Statcast measured batted balls. Those three columns have 68 NaN, not 8. ## Subdirectories `mlb_bat_tracking/` and `mlb_wp/` come from other projects and are **not** touched by the weekly refresh. Their freshness is unrelated to the table above. ## Usage ```python import pandas as pd base = "https://huggingface.co/datasets/yasumorishima/mlb-stats/resolve/main/" pf = pd.read_parquet(base + "park_factors.parquet") print(pf[pf["season"] == 2026].nlargest(3, "pf_3yr")[["team", "venue_name", "pf_3yr"]]) ``` ## Sources and terms - [Baseball Savant](https://baseballsavant.mlb.com/) — MLB Advanced Media - [FanGraphs](https://www.fangraphs.com/) — the three `fg_*` tables - [MLB Stats API](https://statsapi.mlb.com/) — `statsapi_batting` and `statsapi_pitching`; responses state "Copyright MLB Advanced Media, L.P." and refer to - Fetched with [pybaseball](https://github.com/jldbc/pybaseball) and [savant-extras](https://github.com/yasumorishima/savant-extras) This is a derived, aggregated mirror published for research and reproducibility. No licence is asserted over the underlying data, which remains subject to the terms of the sources above; check those before redistributing. Open an issue on the [pipeline repository](https://github.com/yasumorishima/mlb-data-pipeline) for corrections.