import math


def _on_base(base_run_id) -> str:
    """
    Exists Runner
    :param base_run_id: retrosheet base_run_oid
    :return: '1' or '0'(1:True, 0:False)
    """
    if type(base_run_id) == float and math.isnan(base_run_id):
        return '0'
    elif type(base_run_id) == str and len(base_run_id) > 0:
        return '1'
    return '0'