Bueno lo mejor seria q tu consulta fuese de la siguiente manera:
Código PHP:
$cadbusca="SELECT id, subcategory MATCH (subcategory, products) AGAINST ('$busqueda' IN BOOLEAN MODE) AS Score FROM rugs_carpets WHERE MATCH(subcategory, products) AGAINST ('$busqueda' IN BOOLEAN MODE) HAVING Score >= $numero ORDER BY Score DESC LIMIT 50";
Saludos.