One of the most frustrating things I see weak-minded players do is give up on a play. I understand not everyone is wired like Rafael Nadal with a relentless attitude to chase down balls from seemingly impossible situations. However, here is a good trick that makes logical sense and something you can implement into your game right away.
Lets say you are in a tussle and slowly your opponent pushes you deep into the corner. Without meaning to, you cough up a short ball so short, you quickly calculate the odds of winning the point to be less than 10 percent. One option is to give in and just turn around. Another option is to run to the center of the court and see what happens. The BEST option is to guestimate the one place the winner will go and run to that spot. This means taking half the court away and take away the easiest shot for them to hit.
Standing in the middle of the court opens up the edges. However, most people who play great defense have a knack for guessing right. What these players are really doing is reading the ball, the opponents body language, and checking where the most probably place the next ball could potentially go and taking that option away. Make them hit the most difficult shot and maybe if you are strongly covering one-half of the court, good things could happen- like the ball coming onto a crash collision with you.
Like chess, you always want to apply pressure and think a couple steps ahead. Now if you continue to chase these balls down (Lendl said: "I run after everything, even if I think that I can't get there"), however dire the situation may be, and continue to take away half of the court- they will start to feel the pressure deep into the set or match. Easy shots suddenly aren't so easy, muscles start to tighten, and shots that were once manageable without blinking start to feel like catching a mosquito with chopsticks (well maybe not that hard, but anything is possible when you get underneath someone's skin). Good things can happen and these types of points can switch the momentum and cause rookie players to crack mentally.