See the narrative below taken from the APPL Rules of Play.

Match Day Teams:  On match day the captain will bring 6 players to play on 3 doubles teams.  Line-ups identifying the doubles teams on the scoresheet will be exchanged prior to the start of the match after which they may not be changed.  The 3 doubles team partners will stay together for that day’s match unless substitutions are made (see substitution rules).  Captains or their designees are required to be on-site at each match.

Match Process: To begin a match, the visiting teams choose serve, receive or side.  Each doubles team will play 2 games to 11 (win by 2). Teams shall switch sides after the first game.   At the end of the second games (first round), and the fourth games (second round), the visiting doubles teams switch courts to play the next home doubles team noted on the line-up/scoresheet. Therefore, on team match day, each doubles team will play 6 games (three rounds): 2 games against the opposing line 1 doubles team, 2 games against the line 2 team, and 2 games against the line 3 team. Two team points are awarded for each game won by a doubles team. If the losing team scores 6 or more points in a game they are awarded 1 team point.  No team points are awarded for a score of 5 points or less. Whichever team earns the most team points in all the games played in a match, will be the winner of the match and will be awarded a win in their league skill group team standings.