The d ratio is similar to the Bernado Ledoit ratio but inverted and taking into account the frequency of positive and negative returns.
DRatio(R, ...)It has values between zero and infinity. It can be used to rank the performance of portfolios. The lower the d ratio the better the performance, a value of zero indicating there are no returns less than zero and a value of infinity indicating there are no returns greater than zero.
$$DRatio(R) = \frac{n_{d}*\sum^{n}_{t=1}{max(-R_{t},0)}}{n_{u}*\sum^{n}_{t=1} {max(R_{t},0)}}$$
where \(n\) is the number of observations of the entire series, \(n_{d}\) is the number of observations less than zero, \(n_{u}\) is the number of observations greater than zero
Carl Bacon, Practical portfolio performance measurement and attribution, second edition 2008 p.95
data(portfolio_bacon)
print(DRatio(portfolio_bacon[,1])) #expected 0.401
#> [1] 0.4013329
data(managers)
print(DRatio(managers['1996']))
#> HAM1 HAM2 HAM3 HAM4 HAM5 HAM6 EDHEC LS EQ
#> d ratio 0.07248996 0.0001052632 0.03085081 0.1383098 NaN NaN NaN
#> SP500 TR US 10Y TR US 3m TR
#> d ratio 0.04607631 1.361501 0
print(DRatio(managers['1996',1])) #expected 0.0725
#> [1] 0.07248996