The maximum drawdown of a history is its largest fall of wealth from a running peak, as a fraction of the peak (drawdown: Book 2, chapter 29). The drawdown duration of a spell is the time from the peak to the recovery of that peak, or to the end of the history if it has not recovered. The Calmar ratio is the annualised return over the absolute maximum drawdown, traditionally on three years.
rs_perf.histories.rs_perf.dd_probability.