Jupiter's small moons are likely captured objects. I would've expected half of them to be captured in retrograde orbit, between 90 and 180 degrees inclination. But out of 65 lesser satellites, only 11 are not retrograde. (Table) There's a smaller but similar bias for Saturn's moons, but not for those of Uranus or Neptune.
Is there an orbital mechanical explanation for why objects most often are captured in retrograde orbits? Is there some process that gets rid of small moons that are not retrograde?
Inclination and distance of "irregular" Jovian moons, Wikipedia