Abstract: A method for scalably calculating statistics associated with action performances includes obtaining action performance data for one or more entities, where the action performance data comprises at least a number of times each of the one or more entities performed an action during one or more time segments, wherein the action satisfies a user specified criteria. The method also includes generating, based on the obtained action performance data, a data structure including one or more values that are organized according to a number of time segments that have elapsed between an action performance and a most recent previous action performance. Systems and machine-readable media are also provided.