So if for example we have 10,000 test sets x (i) and a threshold of .01, and in only 47 of the test sets do we find that δ (x (i) ) ≥ 2δ (x), the resulting p-value of .0047 is smaller than .01, indicating δ (x) is indeed sufficiently surprising, and we can reject the null hypothesis and conclude A is better than B.