A ternary logic used when you are dealing with three equally unpleasant alternatives rather than two; the third (gripping) hand being dominant or determinative. Expression common among sci fi geeks and computer people.
From a science fiction novel entitled "The Mote In God's Eye" where an intelligent alien race has evolved with two minor arms (with fine fingers for work) on their right and one larger (gripping) arm with three strong fingers on their left.
On the one hand, Obama's a knucklehead and I can't stand him. On the other hand, he still has a lot of people who thinks he walks on water. On the gripping hand, we only have to put up with him for two more years, so we shouldn't bother to try to impeach him.