if (c == 'w') return (x == y && [0, 3, 4, 7].includes(x));
// "Black": search for empty square and allow nearby
for (let i of [0, 3, 4, 7]) {
if (c == 'w') return (x == y && [0, 3, 4, 7].includes(x));
// "Black": search for empty square and allow nearby
for (let i of [0, 3, 4, 7]) {