Fast Swing% / Fast Swing%
Batter
Share of competitive swings at 75 mph or faster. Savant judges 75.0 on the unrounded speed, so the published figure can differ by the swings at exactly 75.0.
Agreement with Savant
Checked nightly. Agreement tolerance: ±0 — in swings, through its numerator fast_swings, judged on the bracket from fast swings without the exactly-75.0 ones to fast swings with them (runbook §60).
Pitcher
Share of competitive swings against this pitcher at 75 mph or faster. Savant judges 75.0 on the unrounded speed, so the published figure can differ by the swings at exactly 75.0.
Agreement with Savant
Checked nightly. Agreement tolerance: ±0 — in swings, through its numerator fast_swings, judged on the bracket from fast swings without the exactly-75.0 ones to fast swings with them (runbook §60).
Shown for: batter and pitcher.
Formula
sum(fast_swings)::real / NULLIF(sum(comp_swings), 0) — competitive swings at bat_speed >= 75 over competitive swings. Savant judges 75.0 on the unrounded speed; the swings published at exactly 75.0 are counted separately as fast_boundary so parity can judge the bracket.
Inputs
pitches.bat_speedplate_appearances.fast_swingsplate_appearances.fast_boundaryplate_appearances.comp_swings
Era caveats
Bat tracking begins 2023-07-14
Savant's bat-tracking fields -- bat speed, swing length, attack angle, attack direction and swing tilt -- are on the wire from 2023-07-14. Every bat-tracking column is empty for 2015-2022, 2023 covers the second half of the season only, and a span that starts earlier counts only the swings from that date. Parity is unaffected: Savant's own 2023 boards carry the same partial season, and the six closed season-sides reconcile to the player. (runbook §59)
Version history
- 2026-09-13 — Facts and aggregates added (M4 S3). (runbook §59)
- 2026-09-13 — Parity-enforced nightly through fast_swings on the bracket [fast − boundary, fast] at tolerance 0. (runbook §60)
- 2026-09-16 — Added to the Explorer and the rolling chart (M4 S5). (runbook §61)