Master Time and Space

Napoleon said "Strategy is the art of making use of time and space. Space we can recover; lost time, never." In tennis, you too will have to deal with these concepts: time and space. Space is the court that you control as well as the court controlled by your opponent. Time is, obviously, the duration that you have available in which you have to make a particular decision. Controlling your opponent's court is your goal (although, you're not trying to invade it with armies but with balls). However, if the opponent controls time, you will not be successful in your campaign. 

Take for example an offensive shot by you. In this example, we'll assume that it's not be a winner but it's pretty close. If you allow your opponent to throw up a defensive lob (pop-up) and you let it come down, bounce and come down again, your initial artillery attack is useless. You controlled some extent of your opponent's court, but he controlled time - in which he recovered back to a central positions. You simply cannot allow the opponent to "press the reset button" in a point and get herself into the court. When you hit a good shot, you have to recognize it right away in order to capitalize on it. Look at the opponent's location in the court. Is she 10 ft behind the baseline? 5 ft outside of the side-lines? Moving backwards? Scrambling?  So, in this example, step in and either belt a swinging volley, punch a regular volley or follow up with another offensive shot. Never allow the opponent to recover "space" with "time". Conversely, if you're on the defense that's exactly what you want to do: buy your way back into the point with a shot that takes a while to get back to the other side of the court (unless you see that the opponent is "bolting in" to control space and time). A lot of juniors get pressed on the defensive and then go for a blasting, Hail Mary shot. Even assuming that you make it, if the opponent gets his racket on the ball, you have no time to recover (in which case, she's controlled both space and time). 

Similarly, you can control more "space" if you play from close into the court than from "the vineyard". If you're 10-12 behind the baseline, you can only home to control time. However, due to the angles, you are relegated to only hitting in certain parts of the court. Conversely, the closer into the court you find yourself, the more the court opens up and the less time the opponent will have to react and make proper decisions.