def is_better(new_metric, current_best_metric, metric_to_watch='acc'):
    """
    Determines which of the two metrics is better, the higher if watching acc or lower when watching loss
    :param new_metric:                 the new metric
    :param current_best_metric:        the compared to metric
    :param metric_to_watch:             acc or loss
    :return: bool, True if new metric is better than current
    """
    return metric_to_watch == 'acc' and new_metric > current_best_metric or (metric_to_watch == 'loss' and current_best_metric > new_metric)