BNS and NSBH merger detection probability in O4c. The red squares in the left-hand panel show the probability that exactly N_O4c2 BNS mergers are detected by the LVK network during O4c2, based on the number N′ = 2 detected in previous runs, according to Eq. (6) and adopting the Jeffreys prior (α = 1/2). The blue circles refer to NSBH instead, assuming N′ = 5. In the right-hand panel, the probability of a number of detections equal or greater than a given minimum, N ≥ N_O4c2 in O4c2, is shown for the same two classes of sources.