def _breakdown_point(n_samples, n_subsamples):
    """Approximation of the breakdown point.

    Parameters
    ----------
    n_samples : int
        Number of samples.

    n_subsamples : int
        Number of subsamples to consider.

    Returns
    -------
    breakdown_point : float
        Approximation of breakdown point.
    """
    return 1 - (0.5 ** (1 / n_subsamples) * (n_samples - n_subsamples + 1) +
        n_subsamples - 1) / n_samples
