NAB Normalized Scores


I am having trouble to interpret the normalized NAB score (Eq. (4) in the conference paper). The result is supposed to be in the range [0, 1], but this depends on how many false positives you get, i.e., if you get too many the score of the detector will be negative and potentially Eq. (4) would produce a negative number.

I wonder if this interpretation is correct. Any feedback appreciated.

Thank you.