Relative occurrence rates of signals in the distance-viewing angle plane predicted for the O4 run. Colors indicate different detection scenarios: events detectable (i) both as GW triggers and kilonovae (green), (ii) as GW signals alone (blue), and (iii) only as kilonovae (“orphan kilonovae,” red). For the kilonova detection, the four diagrams correspond to the limiting r-band magnitudes from 19 to 22. We also indicate the total occurrence rates in each detection scenario, assuming a GW detection rate of 10 yr⁻¹ for O4.