The ALTA Senior Mixed Doubles League is open to men and women 45 years of age and older and plays during the Winter season. Each Senior Mixed season lasts seven weeks plus one round of playoffs that lead to the City Championship at each playing level.
Teams are formed through individual effort at public facilities, neighborhood courts, and private clubs. Playing levels include, from advanced to novice, AA, A, B, and C. Within each level, there are up to 9 flights.
The prior season/year performance of the team and previous levels of its players determine team placement within the levels and flights. Individual players' levels are determined by their prior levels from the following leagues in this order: Senior Mixed level (from most recent past season), Senior Men/Senior Women's level (from most recent past season), Men/Sunday/Thursday Women's level (prior two seasons), Mixed Doubles level (prior two seasons), Senior Day Men/Senior Day Women's level (prior two seasons). Player history in both the Sunday and Thursday leagues the same season will use the higher rating.
The many levels of competition help assure that players are matched against pairs of comparable ability and allows for a highly competitive match and fun tennis environment.