1. A system capable of allowing an analyst to analyze event streams of a user session and graphically display a result, the system comprising: a log file configured to interface to one or more log sessions from a user-generated event stream; a query composer comprising a query language and a front-end filter coupled to the log file, the query composer configured to provide one or more conditions to sort the event stream; and a graph visualizer coupled to the query composer and configured to produce a probability distribution of event nodes from a given node in the event stream.