The perception of the game situation demands looking at the space. The player knows where the lines and the net are, as they are static. But the ball and the opponent move and they are at different places.
If the ball is coming, but it´s still on the other side of the net, you can easily look at the ball and the opponent at the same time. It changes as the ball is approaching. Just before the shot, the ball is here on your right side and the opponent is placing in front of you. You cannot watch two different places at the same time. You have to focus on the ball you hit and locate the opponent based on a lateral blurred image. This is the peripheral vision which can have almost 180 degrees of viewing.
By developing this skill, your decision making improves. Just before the shot, you have to decide where to send the ball. This is why you have to know where the opponent is. Doing so, the selected options will be more appropriate. And that will also improve your way of execute them. If you don´t know where the adversary is but you suppose that, may be you make the right decision. But if you have doubts, you will lose self-confidence and your movements become clumsy.
Other reasons to train peripheral vision
To make decisions, the brain uses oxygen, nerve impulses, energy sources and more. Those supplies are not unlimited. If the brain wastes too much of that in perceiving the opponent who is on the visual periphery, then it perceives that but it cannot make decisions based on this information. From a psychological point of view, there is also a need to save resources. It is difficult to carry out several psychological processes at the same time.
The brain is like a computer, it hangs or resets. Suppose you can perceive the game situation. So you know where you, the ball, the adversary and so on are. But you try to decide where to send the ball and you cannot do it because your brain is blocked although you know what you are trying to do. So, the brain is hanged like the computer which hangs but continues showing the same information on the screen.
Suppose you try to perceive the game situation including peripheral vision and your mind goes blank. At times, you lose the information and you don’t know what you were trying to do. Your brain has been reset.
Whether your brain resets or hangs for moments, the task consumes too many resources. It happens frequently but it doesn´t harm us unless we are playing tennis.
Sometimes, the brain doesn´t hang or reset but wastes too many resources on peripheral vision and all process supported by thinking become difficult including technical adjustments, tactical adjustments, emotional control, analysis of the opponent and more.
How to avoid wasting resources on peripheral vision?
Emotional control is a key. So the ability to process information improves including peripheral vision. If the tennis player presents high stress level, he does not perform an adequate peripheral vision. It´s not possible to perform an appropriate decision making process based on that perception.
The other key is the repetition of peripheral visual perception tasks. As the task becomes easier and automatic, the less resources it consumes. There are a lot of exercises where the athlete looks at a place and have to perceive stimuli located in other sides.
These could be laboratory tasks where the player has to perceive lights from the right or left sides or touch moving points projected in a screen located on the sides. On the other hand, there are exercises which lead the athlete to look at real physical objects moving in a court.
To increase the likelihood of real progress in sport performance, you need to select the right exercises and insert them into a well-designed mental preparation plan. This must take into account not only visual perception, but other elements associated with tennis player´s tactical decision making.