When I got my first Critical Capture on the first time, I was having some struggle of catching Victini in Liberty Garden to the point I'm throwing Timer Balls as the last resort. However, at one point of throwing Timer Balls, I suddenly hear a sharp, flinging sound when I don't expect it, that makes the Timer Ball shakes once and then clicks.
This makes me rejoice, and out of curiosity, starting to search on the net why the fling occurs to me, and finding out that the Critical Capture is the cause, and since then, sometimes when throwing Pokéballs, I'm expecting to hearing the flinging sound so that I can catch Pokémon easier while filling the Dex to make sure it happens often.