Eyes on the ball

Hi! how are you? I asked this question to many coaches but no one could give me a satisfying answer. The problem is their answers make me confuse. the question is

How should I look at the ball?

If my head moves up or down (height wise) because of my stance or bending position does it matter in judging a ball? 

Should its position remain at same height all the time?

I've heard a terminology "line of sight" what is that? 

to me there are two techniques for looking at the ball; 1 constantly looking at the ball during play, 2 shifting the sight between ball and opponent's racket (whenever ball travels to the opponent's side I look at his racket and it helps me to read his next shot and when ball travels to me I look at the ball but it is difficult to shift sight so quickly). Which technique is a better technique and which technique should I stick to?

While receiving a serve where should I look? on the ball which is in the air or at opponent's racket?

While serving is it important to look at the ball or not? other than high toss serves (for 10 inch toss)

I hope you will understand my questions and problems

Please guide me with easy answers. I shall be very thankful.

Hi Ahsan,

Firstly it is important to track the ball all the way through the rally.  It is too difficult to change your focus from the ball to the opponents racket or anything else.  This is something that you can practice in training.  It will take a while to be able to watch the ball constantly and keep your concentration on it for long periods of time.

Secondly, you should try to keep the height of your eyes constant throughout the rally.  If you are jumping up and down it will effect the way you are seeing the ball.  You will notice that the best players keep their heads very still.

When receiving a serve, especially a high toss serve, I think it is better to watch the ball all the way through.  Some players though prefer to watch the bat because it effects you vision, especially if there are big lights overhead.  For a low toss serve, watch the ball all the way through.

While watching the ball you will still see the things that are going on around the ball with your peripheral vision.

The term line of sight, is just the area you are looking within your range of vision.