If the score reaches six points all the game is extended until this margin has been achieved. Numerical scoring is used throughout the tie-break. In doubles, the player whose turn it is to serve is the Server for the first point. Thereafter, each player serves in rotation for two points, in the same order as determined previously in that set, until the winners of the game and set have been decided. Starting with the first point, each service is delivered alternately from the right and left courts, beginning from the right court.
Players change ends after every six points and at the conclusion of the tie-break game.
As indicated, more restrictions are placed on men's draws. Tennis World Team Tennis is a concept, devised by Billie Jean King, which came to fruition in the 1970's and has recently made somewhat of a comeback. The concept gradually died for various reasons in the late 70's but has been revised in a scaled-down form. The Team Tennis franchise is similar to US baseball and football, where teams based in various US cities compete against one another. Unlike baseball and football, team members get paid based on their performance rather than a fixed amount.