Synonyms to flip of a coin

accidentality, actuarial calculation, adventitiousness, blind bargain, break, casualness, chance, chance at odds, destiny, fate, flukiness, fortuitousness, fortuity, fortune, gamble, gambling chance, good fortune, good luck, hap, happenstance, happy chance, heedless hap, how they fall, indeterminacy, indeterminateness, law of averages, lot, luck, matter of chance, moira, opportunity, potluck, potshot, principle of indeterminacy, probability, problematicness, random sample, random shot, risk, run of luck, serendipity, sporting chance, statistical probability, the breaks, theory of probability, toss, toss-up, touch and go, uncertainty, uncertainty principle, whatever comes