• Player A hits all balls cross-court
• Player B hits all balls straight towards the baseline.

Please keep the ball ‘just’ in play not bothering about the height.

In this exercise also, please attack at the net shorter balls from the opponent , and try to win the point.

The most important rule is that you should begin this exercise by each doing a 30  minute training session, - then you improve without realising it, the following: 
leg exercises, ground strokes, placement of shots, anticipation, and overall fitness!!

This is complete when both players attain the discipline to keep the ball in play  for at least 2-4 minutes.

Let your opponent make the errors rather then make the winning shot yourself!!!