- if ( st->key != si.key
- || st->pawnKey != si.pawnKey
- || st->materialKey != si.materialKey
- || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
- || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
- || st->psq != si.psq
- || st->checkersBB != si.checkersBB)