[fix] Non heuristic moves...

connect_four.js

@@ -166,12 +166,57 @@ function scanBoard(b) {
     return [0, []];
 }
 
+function evaluateBoard(b, aiP, huP) {
+    let score = 0;
+
+    // Center column bonus
+    for (let r = 0; r < ROWS; r++) {
+        if (b[3][r] === aiP) score += 3;
+        else if (b[3][r] === huP) score -= 3;
+    }
+
+    // Score a window of 4 cells by piece counts
+    function scoreWindow(c, r, dc, dr) {
+        let ai = 0, hu = 0;
+        for (let i = 0; i < 4; i++) {
+            const v = b[c + i * dc][r + i * dr];
+            if (v === aiP) ai++;
+            else if (v === huP) hu++;
+        }
+        if (ai > 0 && hu > 0) return 0;
+        if (ai === 3) return 50;
+        if (ai === 2) return 5;
+        if (hu === 3) return -50;
+        if (hu === 2) return -5;
+        return 0;
+    }
+
+    // Horizontal
+    for (let r = 0; r < ROWS; r++)
+        for (let c = 0; c <= COLS - 4; c++)
+            score += scoreWindow(c, r, 1, 0);
+    // Vertical
+    for (let r = 0; r <= ROWS - 4; r++)
+        for (let c = 0; c < COLS; c++)
+            score += scoreWindow(c, r, 0, 1);
+    // Diagonal up-right
+    for (let r = 0; r <= ROWS - 4; r++)
+        for (let c = 0; c <= COLS - 4; c++)
+            score += scoreWindow(c, r, 1, 1);
+    // Diagonal down-right
+    for (let r = 3; r < ROWS; r++)
+        for (let c = 0; c <= COLS - 4; c++)
+            score += scoreWindow(c, r, 1, -1);
+
+    return score;
+}
+
 // --- AI -----------------------------------------------------
 function minimax(b, depth, alpha, beta, isMax, aiP, huP) {
     const [winner] = scanBoard(b);
     if (winner === aiP) return 1000 + depth;
     if (winner === huP) return -1000 - depth;
-    if (depth === 0 || isBoardFull(b)) return 0;
+    if (depth === 0 || isBoardFull(b)) return evaluateBoard(b, aiP, huP);
 
     let best = isMax ? -10000 : 10000;
     for (const c of COL_ORDER) {
@@ -196,12 +241,19 @@ function performAiMove(b, aiP, lookAhead, isDemo = false, dPly = 4) {
     const huP = aiP === 1 ? 2 : 1;
     const ply = isDemo ? dPly : lookAhead;
 
-    // Phase 1: instant win / block
+    // Phase 1a: check ALL columns for instant AI win
     for (let c = 0; c < COLS; c++) {
         const r = getFirstEmptyRow(b, c);
         if (r === -1) continue;
         b[c][r] = aiP;
         if (scanBoard(b)[0] === aiP) { b[c][r] = 0; return c; }
+        b[c][r] = 0;
+    }
+
+    // Phase 1b: check ALL columns for opponent block
+    for (let c = 0; c < COLS; c++) {
+        const r = getFirstEmptyRow(b, c);
+        if (r === -1) continue;
         b[c][r] = huP;
         if (scanBoard(b)[0] === huP) { b[c][r] = 0; return c; }
         b[c][r] = 0;