Javascript 4 line solution
```js\nvar btreeGameWinningMove = function(root, n, x) {\n    const count = root => root ? count(root.left) + count(root.right) + 1 : 0;\n    const find = root 
```js\nvar btreeGameWinningMove = function(root, n, x) {\n    const count = root => root ? count(root.left) + count(root.right) + 1 : 0;\n    const find = root => root ? root.val === x && root || find(root.left) || find(root.right) : false;\n    const node = find(root), l = count(node.left), r = count(node.right), p = n - l - r - 1, max = Math.max(l, r, p);\n    return max  > n - max;\n};
['JavaScript']