Rotating players and Flex formats
When the number of players does not divide by four, some sit out each round in turn. Flex formats share playing time fairly and, if needed, rank by average points.
Resting in turn
Four players fill each court; anyone left over rests for a round. Nobody rests twice before everyone has rested once.
Fair standings
If everyone plays the same number of rounds, totals work. If not, organisers often rank by average points per round. The method should be announced before the first ball.
Questions
What happens with an odd number of players in an Americano?
Some players rest each round in turn, and standings may use average points.