4 Fixation Visual System

It isn’t literally possible to “watch the ball” in high level tennis. At least, not all the time. The ball is simply moving too quickly for your eye to track it using smooth pursuit tracking, and as such, you must follow the ball with predictive saccades instead.

This means you need to decide when to fixate on the ball. You’re only going to catch it on your fovea a few times during its flight. Given that, what times should you choose to give your brain maximum information about the ball’s movement?

The four most important parts of the flight, on which you should fixate when receiving a shot, are as follows:

1. Your opponent’s contact
2. Mid-air, on your opponent’s side of the court
3. The bounce
4. Just before your own contact

Ideally, you want to track the ball between these fixations as well, with additional saccades or with smooth pursuit, but often, it’ll be moving too fast for that. When returning fast serves, for example, you’ll typically only have time for these four fixations, and nothing more. (On a really fast serve, 115+ mph or 175+ km/h, you might even need to skip #2).

Rest assured, though: if you perform these four fixations correctly, finding the ball on your fovea, in crystal clear focus, at each one, then your shot will succeed, no matter how fast the incoming ball.

Only four fixations?

All tennis shots are different. Many can be tracked using smooth pursuit – just follow the ball with your eyes, and you’ll see it clearly. When receiving these shots, you’ll perform many, many fixations, without even thinking about them.

The reason we’re discussing these four specific fixations is that they form the cornerstone of receiving any tennis ball, even one struck exceptionally well; the advantage gained by using them will not decrease the higher in level you progress, as the tracking task becomes more difficult. The information gained at these four fixations is both necessary and sufficient for success: see the ball well at these points, and you can hit it, no matter how complicated its movement.

On slow shots, you’ll probably be able to see the ball clearly at more than just these four points, and that’s great – track a slow ball with as many fixations as you want, but be comfortable receiving a ball while only catching it in focus a few times. By keeping these four fixations at the center of your visual system, you ensure that your tracking won’t break down against more challenging balls, on many of which smooth pursuit tracking will be unavailable.

Example – Serve Return

If you’re used to simply “watching the ball” on serve returns, as you move up in level, you may start losing sight of it. On those faster, spinnier serves, the ball is moving too quickly through your field of vision to track using smooth pursuit. If smooth pursuit is all you’ve practiced, this puts you in a tough spot.

Your brain will try to switch to predictive saccades, because that’s what the eye naturally does to track fast moving objects, but the “predictive” part of the “predictive saccade” takes time to master. Predicting a later location of the ball based on early flight information is difficult, and if you’re not used to doing it, you’re probably not going to do it very well.

That’s why it’s so important to attentively and intentionally fixate on the right points even on slower balls, on which you can get away with just randomly watching it. We need to build a habit of doing things like watching the bounce, because that practice, those repetitions, are what scale well as we move up in level.

Catch-Up Verses Predictive Saccades

When you try to track a ball using smooth pursuit, and fail because the ball’s speed is too high, you’ll end up performing catch-up saccades – your eyes will jump forward to the object after you lose it during smooth pursuit tracking. These saccades won’t end on useful points like the bounce, but will instead be to random points. As a result, the visual information gained from them will be severely limited.

By building our visual system around fixations on:

• The opponent’s contact,
• mid-air on your opponent’s court,
• the bounce, and
• our own contact,

We ensure that each of our few fixations provides maximum possible visual information to our brain. With the information provided from these four fixations, we have enough position and velocity information to hit the ball. Since we can fixate on these points, and gather the information therein, using saccades, we don’t require smooth pursuit tracking to succeed. Even when the ball is moving extremely quickly, we’ll perform these same fixations, see the ball clearly at the same points, and by doing so, understand exactly where it is and how it’s moving.

Relative Ball Speed

Predictive saccades are necessary when the speed of the ball relative to your eye is fast. It doesn’t matter how fast the ball is moving in space, but rather how quickly it’s crossing your field of vision.

This means that, often, you’ll be able to track the ball easier on your opponent’s side of the net. When the ball is far away from you, even though it’s moving quickly through space, it’s moving through your field of vision slowly.

The same idea applies for balls hit up the middle, right to you. They’re easier to track, because they aren’t crossing your field of vision. Even though the ball is traveling the length of the court, it might only move a few degrees through your vision.

Difficult balls, on the other hand, are close to you, and moving away from you. This is one of the reasons hitting out of the middle is so effective – by causing the ball to aggressively cross your opponent’s field of vision, you are making their tracking task more difficult.

This brings us back to predictive saccades. Often, your final fixations must be saccadic jumps, even when smooth pursuit was available early in the tracking process. This is why many tennis players refer to having their eyes “lie in wait” for the bounce or contact point. Once the ball is sufficiently close to you, it is crossing your field of vision too quickly to track without saccades. You must perform predictive saccades to the bounce and contact, such that, at those points, you catch the ball in clear focus.

Pick One (Maybe Two)

Do not try to verbalize all four fixations in your mind at once. It’s not going to work. Seeing the ball is a mentally taxing task, and as such, your brain requires almost 100% of its mental resources to perform it adequately. If you’re thinking too much, even if those thoughts are about vision, you’re actually going to see worse.

Pick one fixation at a time, and work on that one.

If your mind is totally clear other than your vision practice – you aren’t thinking about your feet, or some random injury, or your technique, etc – then you can try two at once. Tim Gallwey recommends “bounce, hit,” focusing on tracking the ball on your side of the net. My personal favorite is “hit, bounce” to ensure attentiveness in the opponent’s court as well.

Only consciously focus on one or two, and let the others happen naturally. If the others don’t happen naturally, well, you’ve got work to do, but that work isn’t thinking about them all at once. Again, that’ll make you see worse. That work constitutes drilling one fixation, then drilling another, then going back to the first, then back to another, until you’re seeing them all by habit, without the need for conscious effort.