Stronger player plays middle shots. Advantage is that area is well defined. Disadvantage is that opposite team can tire one player. One player plays the forecourt and the other plays the backcourt when attacked.
Advantage is that the player at the net can put away poor returns and block crosscourt shots.
Disadvantage is that the midcourt area along the sidelines is vulnerable. Students will play a game of doubles to 5 using up and back formation.