DONT FOLLOW THE BALL
Ball watching offers few clues as to where your opponent is likely to hit to. Instead, body position, balance, spacing from the ball and racket angle are better indicators.
Comfortable vs uncomfortable
If your opponent is comfortable, getting a ball, then their options many and varied. If however, they are uncomfortable, on defence, off-balance, reaching, rushed, lunging low and wide, or even high. The last place they will want to hit is down the line, this offers a huge advantage and you can be happy to leave your middle court position and attack the centre window.