In this paper a tool for relative efficiency assessment, namely Data Envelopment Analysis (DEA) was used to measure the efficiency of coach-corps' conducting games of 2003 Chinese Professional Baseball League (CPBL). Researcher showed how to use DEA to model DMUs that procedure in two stages, with output from the first stage becoming input to the second stage. The model was applied to coach-corps' performance for six teams of CPBL, demonstrating its advantages over a standard DEA model. It also detected inefficiencies that standard DEA models miss. In addition, the model distinguished inefficiency items in the first stage from that in the second stage, allowing managers to target inefficient stages for two-stage production process to establish teams' greatest victory.