A computer-implemented method for operating a league using at least one fantasy server system includes the following. Fantasy player information including performance history of one or more real-world athletes selected as fantasy players is provided. The fantasy player information is updated in real-time based on fantasy player performance information from a real-world performance. At least one substitution factor is provided. A real-time injury information is received. A real-time fantasy player substitution is determined based on the real-time injury report and the at least one substitution factor.