My father played Carom with gusto and skillfully employed many different kinds of shots, including the scissor shot. As much as I remember, in a scissor shot you place your index finger slightly on top of your middle finger, with the middle finger pushing forward but being held back by the index finger, creating the requisite tension before the middle finger breaks free and hits the striker, releasing that pent-up force onto the striker, as the index finger recoils.
A scissor shot is the only way I can think of to describe the distinctive way in which my father used to “snap” his fingers. He would curl the fingers of his left hand as if to make a fist (but not too tightly) and putting it just behind his shooting hand, play the scissors shot, with his index finger recoiling back and falling on his clenched fist, hitting it in the crevasse between his index and middle finger, making a very peculiar “snapping” sound.
This was something he did, seemingly unconsciously – an idle habit of sorts.
Once in a while I catch myself snapping my fingers like my dad used to, and I am reminded even if I don’t reminisce. I am reminded, when I refer to an idle habit of his as something he used to do and not as something he does (Does he still do that? I don’t know), of the temporal distance between known and unknown.