Too many times, players wait until they miss the ball (in the net or out of bounds) before they decide to make an adjustment to their stroke. Not only has the player lost the point but she may have, in fact, practiced doing something wrong 4, 6 or 6 shots in a row. This makes the road to adjustment a lot more difficult because first you have to unlearn the bad shot before you master the good shot. Instead of waiting for the actual miss to happen, try to make small adjustments throughout the point. Set up imaginary "targets" on top of the net and figure out how your shot measures up with the intended target. This is similar to artillery warfare where the first blast is used to determine the coordinates of the impact and adjustments are made to subsequent artillery fire to take into account wind, elevation, etc. In war, you don't wait until you run out of cannonballs and then say "oops, I guess I should've been aiming more to the right and higher". No, you make small adjustments along the way. Same with tennis; aim for particular spots on top of the net and know - from practice - that if you hit "X" the ball will end up going to "Y" (i.e. the on-court, ultimate target). If you see that your shots are starting to slip from Green to Yellow and from Yellow to Red (picture on the left), stop the bleeding immediately. Make the adjustment while the ball is in play. Same concept applies when your shots are starting to land closer the the line than intended (second image). If you see that the shots are flirting with the lines, throttle it back a little bit (more spin; maybe less power) and bring them back to at least yellow or, preferably, to the blue zone. Force your opponent to hit one more shot. Never give him the satisfaction of putting yourself in the position where you're beating yourself. Make him beat you; make him hit 48 winners. Good things will happen for you if you force your opponent to concentrate an extra shot. Just imagine all the easy sitters that you have missed in your career. Unless the other kid is a "world beater" - ehhem...he's not - you will many extra points when you force another shot back in play. And points add up.