Split-FingerArsenal Shape: Armside Drop
Δ HB -1.8in · Δ VB -7.6in
Current: HB 8.8in / VB +5.6in
Recommended: HB 7.0in / VB -2.0in
Optimization diagnostic / KC
Bailey Falter
Bailey Falter's tools (48) outpace production (31) by 17 points. Primary finding: existing split-finger is present, but its movement shape does not currently cover the desired armside-drop window. Also flagged: Arsenal Shape: Gloveside Sweep; Usage Underuse: Curveball. Most actionable fix: reshape existing split-finger to add armside drop rather than developing a new pitch from scratch.
Data window 2026-05-17 / 2026-05-31Confidence HIGH
Optimization map
Arsenal shape map
Hover each pitch to inspect current usage, movement shape, and whiff context beside the written diagnosis.
ride
armside
gloveside
Movement reshape
Pitch movement dual-view
Current shape against the recommended movement window. Animation starts when this section scrolls into view.
SliderArsenal Shape: Gloveside Sweep
Δ HB -6.6in · Δ VB +0.4in
Current: HB -2.4in / VB +1.6in
Recommended: HB -9.0in / VB +2.0in
Diagnosis
Fixable gaps
| Signal | Cause | Fix | Confidence |
|---|---|---|---|
| Arsenal Shape: Armside Drop0.85 | Existing Split-Finger is present, but its movement shape does not currently cover the desired armside-drop window. | Reshape existing Split-Finger to add armside drop rather than developing a new pitch from scratch.Shape refinement would improve platoon coverage while preserving the existing usage signal. | HIGH |
| Arsenal Shape: Gloveside Sweep0.70 | Existing Slider is present, but its movement shape does not currently cover the desired gloveside-sweep window. | Reshape existing Slider to add gloveside sweep rather than developing a new pitch from scratch.Shape refinement would improve platoon coverage while preserving the existing usage signal. | HIGH |
| Usage Underuse: Curveball0.70 | Curveball grades as the best pitch (whiff 33.0%, CSW 42.9%) but is only thrown 16.6% of the time | Increase Curveball usage to at least league-average for that pitch typeUsage rebalancing is the simplest optimization with immediate impact | MEDIUM |
| Usage Overuse: Four-Seam Fastball0.60 | Four-Seam Fastball grades as the weakest pitch (whiff 0.0%, CSW 24.8%) but is thrown 55.7% of the time | Reduce Four-Seam Fastball usage in favor of higher-performing offeringsUsage rebalancing is the simplest optimization with immediate impact | MEDIUM |
Arsenal / metrics
Underlying components
| Component | Usage | Velo | Whiff |
|---|---|---|---|
| Four-Seam FastballFF | 56% | 91.6 | 0.0% |
| SliderSL | 34% | 82.1 | 14.8% |
| CurveballCU | 17% | 77.2 | 33.0% |
| Split-FingerFS | 6% | 85.1 | 0.0% |
| SinkerSI | 3% | 91.2 | 100.0% |