The list of substitutes changes year to year. Generally those thinking about joining the League or those that recently “retired” fill in. As a sub, you could most likely play every week if so desired. Your best bet is to know golfers that are interested in playing and ask them personally – that has the highest chance of success. If you do not know anyone, you can visit the IMAgolfer site and find a list of subs (and their e-mail) under Golfers -> Directory -> Subs. E-mail someone directly has a higher chance of success. Last, and usually less successful, is to go to Tee-Times -> Schedule or Request a Sub. This will mass e-mail everyone but the impersonal request only occasionally works.