the method provides for the fitting of a different distribution to the tail of a distribution of continuous data , than that distribution fitting to the rest of the distribution . by fitting a distribution to this set of occurrences only , better distributions shapes are obtained for that part of a distribution which might otherwise be overly sensitive to individual or small numbers of occurrences . over sensitivity can make such distributions unreliable in situations where their value is compared with the value of another distribution . a distribution which does not decline quickly to zero is preferred for the tail , for instance a heavy tailed distribution .