Volleyball drill: king of court

Along both sides of the field 3 players line up.
The other players stand outside the field.

Side A passes. (if serve is not over, trainer throws a ball
)Side B does 3 pass game. (Anti-slip mat attached to the net -> passer runs to it) -
Pass goes to player left -> player right passes - Pass goes
to player right -> player left passes - Pass goes to
player in the middle -> player right passes