 After Hempel’s pioneering work in 1948, various probabilistic measures of explanatory power have been proposed (Hempel 1965; Hintikka 1968). Most of them demand that the explanatory theory \(h\) should be positively relevant to the empirical data \(e\). This is the case also with the particular proposal   \[ \frac{P(h\mid e) - P(h\mid\neg e)}{P(h\mid e) + P(h\mid\neg e)} \]   defended by Schupbach and Sprenger (2011) as the unique measure which satisfies seven intuitively plausible adequacy conditions.