In horse racing, a trifecta is when you correctly bet on the first, second, and third place horses. The roots seem to be "tri" meaning "three" and "fect" probably from "perfect." Dropping the effeminate a-ending in favor of the more masculine and vigorous or-ending was a natural step. And though far from perfect, we try our best. It's like the proverb says: "go big or go home."