GUIDES · BETSLIP DOCTOR
What should I compare before treating DRS, UZR and Statcast fielding run value as interchangeable?
Check each metric's data source, components, position coverage, season and calculation before comparing its run value. DRS and UZR use different formulas even though they assess overlapping defensive skills. Statcast Fielding Run Value combines Statcast measures and position-specific run conversions, so the three totals are not interchangeable readings of one identical model.
For Bettors and cappers learning to read baseball records · Updated
DRS and UZR overlap, but their formulas differ
Defensive Runs Saved and Ultimate Zone Rating both express defense in runs relative to average and consider overlapping areas such as errors, range, outfield arm and double plays. MLB describes both as using Baseball Info Solutions data, while noting that their formulas differ.
A shared run scale does not make the inputs or calculation identical. Before comparing two totals, check the source, season, position and methodology used for each figure.
Fielding Run Value combines Statcast components
Statcast Fielding Run Value combines Statcast defensive measures on a run scale. Its components depend on the play and position: the glossary describes conversions for Outs Above Average and separate catching components such as framing and blocking.
A composite with position-specific components is not automatically a substitute for DRS or UZR. Compare which plays and skills are included, how the values are converted to runs, and whether the position and season match.
A fictional comparison checklist
Hypothetical methodology matrix: DRS — source: Baseball Info Solutions; components include errors, range, outfield arm and double plays; check the season and position coverage before comparing. UZR — source: Baseball Info Solutions; overlapping defensive components but a different formula; check the season and covered plays. Fielding Run Value — source: Statcast; component mix and run conversions vary by position. Conversion from one metric's total to another is left blank unless a source defines it. The matrix helps a reader keep unlike totals separate instead of averaging them.
Related questions
Do DRS and UZR use the same formula?
No. MLB says they use overlapping defensive categories but different formulas.
Is Statcast Fielding Run Value a synonym for DRS?
No. It combines Statcast defensive components and run conversions; compare its coverage and calculation with the other metric.