this.checkFlags = { w: 0, b: 0 };
const flags = fenflags.substr(4); //skip first 4 digits, for castle
for (let c of ["w", "b"]) {
this.checkFlags = { w: 0, b: 0 };
const flags = fenflags.substr(4); //skip first 4 digits, for castle
for (let c of ["w", "b"]) {