proj-v1 sanity fixes (caught in the real-data induction)

1. matchupRead fly-ball signal: the batter metrics `gb_pct_bb`/`fb_ld_pct` are
   MISLABELED — they're exit velocities by batted-ball type (Judge fb_ld_pct =
   100.3 mph, not a rate), not ground/fly RATES. Switched fly-ball lean to
   avg_launch_angle (league p10/p50/p90 = 7.1/13.9/20.1°), the correct signal.
2. Absolute rate now fits the FULL season (recency-weighted), not a 20-game
   window: the window under-sampled rare stats — Judge HR projected 0.11 vs his
   0.28 season rate (a fake -32pt edge). Now point=0.27 (matches season); the
   last-5-2x recency lean is preserved.

Post-fix induction (real statsapi logs + real statcast): Judge HR 0.27 (P>=1
0.235 vs book 0.42 -> flags the juiced over), Judge TB P>=2 0.548 vs 0.48
(+6.8pt), thin-hot 3-game P>=1 0.726 / P>=3 0.164 (credible low, thin high),
.300 hitter != 3.0. proj-v1 suites 23/23.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCNgGSt5qvcLxaeQqa7Zpj

src/services/projection/matchupRead.js

@@ -64,28 +64,29 @@ function classifyArsenal(pitchMix) {
 }
 
 /**
- * hitterProfile(batterRow) — the aggregate tendencies we DO have. gb/fb lean
- * comes from gb_pct_bb vs fb_ld_pct in the metrics blob (batted-ball type).
+ * hitterProfile(batterRow) — the aggregate tendencies we DO have.
+ *
+ * FLY-BALL lean comes from avg_launch_angle (league p10/p50/p90 = 7.1/13.9/20.1°
+ * verified in prod). NOTE: the metrics blob's `gb_pct_bb` / `fb_ld_pct` are
+ * mislabeled — they are EXIT VELOCITIES by batted-ball type (Judge fb_ld_pct =
+ * 100.3 mph, not a rate), NOT ground/fly RATES. Launch angle is the correct,
+ * unambiguous air-vs-ground signal. (Caught in the proj-v1 sanity induction.)
  */
 function hitterProfile(row) {
   if (!row) return null;
   const m = row.metrics || {};
-  const gb = num(m.gb_pct_bb);
-  const fb = num(m.fb_ld_pct);
-  let flyLean = null;
-  if (gb != null && fb != null && (gb + fb) > 0) flyLean = fb / (gb + fb); // 0..1, high = fly-ball
   return {
     whiff: num(row.whiff_pct) ?? num(m.whiff_pct),
     chase: num(row.chase_pct) ?? num(m.chase_pct),
     hard_hit: num(row.hard_hit_pct) ?? num(m.hard_hit_pct),
-    fly_lean: flyLean, // fraction of batted balls in the air
+    launch_angle: num(row.avg_launch_angle) ?? num(m.avg_launch_angle), // ° — higher = more air
   };
 }
 
 // League anchors (2026 percentiles, verified in prod) — the neutral point each
 // tendency is measured against, so "high"/"low" means relative to the league.
 const ANCHOR = Object.freeze({
-  arsenal_whiff: 22, hitter_whiff: 24, hard_hit: 38, fly_lean: 0.5,
+  arsenal_whiff: 22, hitter_whiff: 24, hard_hit: 38, launch_angle: 13.9,
 });
 // Max single-component lean and total matchup lean — coarse read, small effect.
 const COMP_MAX = 0.05;
@@ -118,7 +119,7 @@ function matchupMultiplier({ arsenal, hitter, statType } = {}) {
   //     fly-ball arsenal lets a fly-ball hitter elevate. DERIVED: sinker share
   //     vs hitter fly lean.
   const groundy = clamp(arsenal.sinker_pct - 0.20, -0.5, 0.6) / 0.6; // >20% sinker = groundy
-  const flyBat = z(hitter.fly_lean, ANCHOR.fly_lean, 0.2);
+  const flyBat = z(hitter.launch_angle, ANCHOR.launch_angle, 6); // p90 20° → ~+1, p10 7° → ~-1
   const airSuppress = clamp(groundy * Math.max(0, flyBat), -1, 1); // groundy arm vs fly bat → power down
 
   // (3) HARD-CONTACT axis — an arsenal that allows hard contact, faced by a

src/services/projectionChallenger.js

@@ -87,9 +87,14 @@ function parkBaselineFromLogs(gameLog, playerTeamAbbr) {
   return factors.reduce((a, b) => a + b, 0) / factors.length;
 }
 
-/** Recency-weighted observed counts (last-5 games weighted 2×, like the champion). */
-function recencyWeighted(gameLog, field, window = 20) {
-  // gameLog is most-recent-LAST (statsapi order); take the tail as recent.
+/**
+ * Season-with-recency observed counts: the FULL season anchors the absolute rate
+ * (a 20-game window under-samples rare stats — a slugger's HR drought produced a
+ * 0.11 point vs a 0.28 season rate, a fake -32pt edge, caught in the induction),
+ * with the last 5 games weighted 2× for current form (as the champion does).
+ */
+function recencyWeighted(gameLog, field, window = 200) {
+  // gameLog is most-recent-LAST (statsapi order); the tail is the recent form.
   const rows = (gameLog || []).filter((g) => g && g.stat);
   const recent = rows.slice(-window);
   const n = recent.length;

tests/unit/projectionChallenger.test.js

@@ -14,9 +14,9 @@ const FB_ARM = mr.classifyArsenal([
   { type: 'FC', usage_pct: 20, whiff_pct: 18, hard_hit_pct: 40 },
   { type: 'CU', usage_pct: 15, whiff_pct: 20, hard_hit_pct: 30 },
 ]);
-// A fly-ball, hard-hit hitter; and a whiff-prone one.
-const flyBat = { whiff_pct: 22, chase_pct: 28, hard_hit_pct: 46, metrics: { gb_pct_bb: 30, fb_ld_pct: 55 } };
-const whiffBat = { whiff_pct: 34, chase_pct: 34, hard_hit_pct: 34, metrics: { gb_pct_bb: 45, fb_ld_pct: 40 } };
+// A fly-ball (high launch angle), hard-hit hitter; and a whiff-prone, flatter one.
+const flyBat = { whiff_pct: 22, chase_pct: 28, hard_hit_pct: 46, avg_launch_angle: 20 };
+const whiffBat = { whiff_pct: 34, chase_pct: 34, hard_hit_pct: 34, avg_launch_angle: 10 };
 
 describe('arsenal classification', () => {
   it('buckets usage by pitch family + carries whiff/hard-hit tendency', () => {