Anticipating versus Reacting versus Responding
One of the things I've always taught is that, in most circumstances, you should react, not anticipate, in a rally. This is because way too often players do anticipate a certain return, and are caught off guard when they don't get that shot. For example, when they attack, many players anticipate a crosscourt return, and so are caught off guard if it is returned down the line. Or they serve short backspin and anticipate a long backspin return. There are times where you can anticipate, such as against a player who does return your attacks crosscourt over and over (as many do), or against an opponent who does push your short backspin serves back long over and over (as many do). In these cases, you can anticipate, but you still have to react if you don't get the ball you expect.
However, in the context I'm using, perhaps I should instead say a player should respond, not react. What's the difference? React may imply that you are simply doing something that you are forced to do, i.e. in reaction to what the opponent is doing. It almost implies that the opponent is in charge, forcing you to react to his actions. Respond implies that you are choosing your response, and that you are in control. It's still a reaction, but it's a more selective reaction.
For example, suppose an opponent attacks hard to your backhand. You could react and block it back crosscourt, the most natural and easy way to return it. Or you could respond by noting the opponent is waiting for that ball and is already edging over, and instead respond by blocking it down the line. Or suppose your opponent serves short backspin. You could react and simply push it back long, the most natural and easiest way to return it. Or you could respond by noting the opponent is waiting to loop that ball, and instead respond by pushing short or flipping.