An accounting system for use with at least one gaming machine having one or more games stored thereon is provided. The accounting system includes a memory means operatively connected to the gaming machine, wherein the memory means comprises a set of active game meters for each active game on the gaming machine, and one set of removed game meters accumulating data corresponding to all games removed from the gaming machine. The accounting system also includes an accounting processor for accessing the game meters and using a theoretical win value to determine the overall gaming machine performance.