In progress · Econometrics class project
Does throwing harder mean more strikeouts?
Research question
What is the effect of average fastball velocity on strikeouts per nine innings (K/9) among MLB pitchers?
- Unit of observation
- Individual MLB pitchers, one observation per pitcher
- Sample
- Pitchers with at least 50 innings pitched in a single season
- Season
- 2025 MLB regular season
- Data sources
- FanGraphs and Baseball Savant (Statcast)
Variables
| Role | Variable | Definition | Data source | Type |
|---|---|---|---|---|
| Dependent | K/9 | Strikeouts per nine innings pitched | FanGraphs (pitcher leaderboard, standard stats) | Continuous |
| Independent | Velocity | Average four-seam fastball velocity (mph) | Baseball Savant (Statcast pitch stats) | Continuous |
| Independent | Spin rate | Average four-seam fastball spin rate (rpm, revolutions per minute) | Baseball Savant (Statcast pitch stats) | Continuous |
| Independent | Breaking ball % | Percent of pitches thrown that are breaking balls (slider and curveball) | FanGraphs (pitch type leaderboard: SL% + CU%) | Continuous |
| Independent | Age | Pitcher age in years | FanGraphs (pitcher leaderboard) | Continuous |
| Independent | Starter | 1 if starter (games started ÷ games pitched ≥ 0.5), 0 if reliever | FanGraphs (G and GS, standard stats) | Binary |
How "starter" is defined
A pitcher counts as a starter when at least half of his appearances are starts (games started ÷ games pitched ≥ 0.5).
- 32 games, 32 startsGS/G = 1.0Starter = 1
- 65 games, 0 startsGS/G = 0Starter = 0
- 20 games, 8 startsGS/G = 0.4Starter = 0
Results coming soon...
Follow @fieldhouse_media for updates as the project comes together.