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Core ruination, utter failure, complete devastation, intractable destruction, or any other extremely undesirable outcome resulting from an event never seen coming or seemingly so unlikely as to warrant no consideration in the first place. Such occurrences have popularly become known as 'black swans'. The word is derived from kurtosis, used in statistics to measure the likelihood of extremely unlikely events. A higher kurtosis value indicates that extreme events constitute a higher proportion of the possible outcomes associated with any given event, though this can only be discerned after such events occur. This is more commonly known as the 'fat-tail' of a probability distribution.
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