accidentality actuarial calculation adventitiousness blessing break casualness chance destiny fate felicity flukiness fortuitousness fortuity fortunateness fortune gamble good fortune hap happenstance happy chance happy fortune heedless hap how they fall indeterminacy indeterminateness law of averages lot luck luckiness moira opportunity principle of indeterminacy probability problematicness random sample risk run of luck serendipity smiles of fortune statistical probability the breaks theory of probability uncertainty uncertainty principle whatever comes