The Arm-Angle Gambit: We Went Looking for the Cheat Code. We Found a Tax.
Pitchers across baseball are dropping their arm slots, chasing the pitch-lab promise that a lower release unlocks a sweeper and a new level. We priced the gambit within-pitcher across 374 arms, two independent methods, two adversarial review rounds. The slot credit is indistinguishable from zero five different ways — and the study's most interesting number (+0.28 runs/100 for the bundled repertoire change) died in cross-review as target leakage; rebuilt clean, both methods land at ≈+0.03, the same as pitchers who never moved. The one effect that survives: droppers lose an average 0.46 inches of four-seam ride (10 of 15, Wilcoxon p=0.011) while stable arms gained. The scoreboard among the 16 droppers: nine better, seven worse — a coin flip. Early-signal by design; full re-test queued for the All-Star break.