Player Plus modeled ratio translating peak torso (chest) kinematic dominance into downstream lead-arm peak speed—mirror the Efficiency / kinematic Gain label from SportsBox verbatim. Distinct from Release Factor (mph) and from positional X-Factor degrees.
Units: ratio
Why it matters
Targets kinematic whip efficiency between torso and arms before wrists release.
When the number looks wrong or noisy
Timestamp misalignment between peaks corrupts ratios—same export/detector build required.