The USTA's Quick Start Tennis is a graduated length system with two stages of play before progressing to a 72-foot full court: The first stage for beginning players advocates a 36-foot long court. If a tennis court is used, simply play the 36-foot length from doubles sideline to doubles sideline. The balls recommended for this 36-foot red stage court are the softball size red-colored "Quick Start 36 Foam" OR the red-colored "Quick Start 36" low-compression balls, which are 15% larger than regular tennis balls. These balls rebound slowly off the racquet and lower off the ground, allowing the children to swing freely while still controlling the balls with more success.
The second stage moves children and all beginning players to a 60-foot court. This can be achieved by using lines to "shorten" a regular tennis court by bringing in the baseline 9 feet on each side (or just setting up this length in a gymnasium. NOTE: Regular tennis balls bounce too quickly to play tennis on the slick floors of gymnasiums, but the slowest bouncing 36-foot stage balls are hardly affected and maintain their slow-bouncing characteristics.