Sessions 5-7a: 955 tests, deployment ready

src/services/lineDiscrepancyDetector.js

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+const SHARP_BOOKS = ['pinnacle', 'circa', 'bookmaker'];
+const SQUARE_BOOKS = ['draftkings', 'fanduel', 'betmgm', 'caesars', 'fanatics', 'bet365'];
+
+/**
+ * Detect discrepancy between sharp and square book consensus lines.
+ * @param {Array<{book: string, line: number}>} propLines
+ * @returns {object} { discrepancy, gap, sharp_consensus, square_consensus }
+ */
+function detectDiscrepancy(propLines) {
+  if (!propLines || propLines.length === 0) {
+    return { discrepancy: false, gap: 0, sharp_consensus: null, square_consensus: null };
+  }
+
+  const sharpLines = propLines.filter(p => SHARP_BOOKS.includes(p.book.toLowerCase()));
+  const squareLines = propLines.filter(p => SQUARE_BOOKS.includes(p.book.toLowerCase()));
+
+  if (sharpLines.length === 0 || squareLines.length === 0) {
+    return { discrepancy: false, gap: 0, sharp_consensus: null, square_consensus: null };
+  }
+
+  const sharpConsensus = sharpLines.reduce((s, p) => s + p.line, 0) / sharpLines.length;
+  const squareConsensus = squareLines.reduce((s, p) => s + p.line, 0) / squareLines.length;
+  const gap = Math.abs(sharpConsensus - squareConsensus);
+
+  return {
+    discrepancy: gap > 0.5,
+    gap: Math.round(gap * 100) / 100,
+    sharp_consensus: Math.round(sharpConsensus * 100) / 100,
+    square_consensus: Math.round(squareConsensus * 100) / 100,
+    sharp_books_used: sharpLines.length,
+    square_books_used: squareLines.length,
+  };
+}
+
+/**
+ * Detect steam move: 0.5+ movement at 3+ books within 10 minutes.
+ * @param {Array<{book: string, line: number, timestamp: string}>} movements
+ * @returns {object} { steam_move, books_moved, magnitude, window_minutes }
+ */
+function detectSteamMove(movements) {
+  if (!movements || movements.length < 3) {
+    return { steam_move: false, books_moved: 0, magnitude: 0, window_minutes: 0 };
+  }
+
+  const sorted = [...movements].sort((a, b) => new Date(a.timestamp) - new Date(b.timestamp));
+  const windowMs = 10 * 60 * 1000; // 10 minutes
+
+  for (let i = 0; i < sorted.length; i++) {
+    const windowStart = new Date(sorted[i].timestamp).getTime();
+    const windowEnd = windowStart + windowMs;
+
+    const inWindow = sorted.filter(m => {
+      const t = new Date(m.timestamp).getTime();
+      return t >= windowStart && t <= windowEnd;
+    });
+
+    // Group by book, find those with 0.5+ movement
+    const bookMovements = {};
+    for (const m of inWindow) {
+      if (!bookMovements[m.book]) bookMovements[m.book] = [];
+      bookMovements[m.book].push(m.line);
+    }
+
+    const significantMoves = Object.entries(bookMovements).filter(([_, lines]) => {
+      if (lines.length < 2) return false;
+      const range = Math.max(...lines) - Math.min(...lines);
+      return range >= 0.5;
+    });
+
+    // Also count books that appear with already-moved lines (single entry with magnitude info)
+    const booksWithMovement = inWindow.filter(m => Math.abs(m.line) >= 0.5);
+    const uniqueBooks = new Set(booksWithMovement.map(m => m.book));
+
+    if (uniqueBooks.size >= 3 || significantMoves.length >= 3) {
+      const allMagnitudes = booksWithMovement.map(m => Math.abs(m.line));
+      return {
+        steam_move: true,
+        books_moved: Math.max(uniqueBooks.size, significantMoves.length),
+        magnitude: Math.round((allMagnitudes.reduce((s, v) => s + v, 0) / allMagnitudes.length) * 100) / 100,
+        window_minutes: 10,
+      };
+    }
+  }
+
+  return { steam_move: false, books_moved: 0, magnitude: 0, window_minutes: 0 };
+}
+
+/**
+ * Get reliability score for a prop type in a sport from historical accuracy.
+ * @param {string} propType
+ * @param {string} sport
+ * @returns {number} Reliability score 0-1
+ */
+function getReliabilityScore(propType, sport) {
+  const reliabilityMap = {
+    nba: {
+      points: 0.72,
+      rebounds: 0.65,
+      assists: 0.68,
+      threes: 0.60,
+      steals: 0.45,
+      blocks: 0.42,
+      pts_rebs_asts: 0.70,
+    },
+    mlb: {
+      hits: 0.55,
+      home_runs: 0.40,
+      rbis: 0.48,
+      stolen_bases: 0.52,
+      strikeouts_pitcher: 0.65,
+      earned_runs: 0.58,
+      total_bases: 0.53,
+    },
+  };
+
+  const sportMap = reliabilityMap[sport.toLowerCase()];
+  if (!sportMap) return 0.50; // default
+  return sportMap[propType.toLowerCase()] || 0.50;
+}
+
+module.exports = {
+  SHARP_BOOKS,
+  SQUARE_BOOKS,
+  detectDiscrepancy,
+  detectSteamMove,
+  getReliabilityScore,
+};