When you watch professional players return serve, they rarely look rushed, and when a player hits heavy spin at them, they never look bothered. There’s a clip from an exhibition tournament were Federer requests a serve “Right to the forehand, really slow.”
What’s really slow to him?
113mph (182 km/h). That’s what Roger Federer considers a “really slow” serve, when it comes right to his forehand.
Now, 113 isn’t slow if it hits a corner, or if it spins into the body (which the serve in the clip actually did), but as far as a pure fastball, 113 is actually slow for a high level returner, and yet most 3.5 adult players would be lucky to even hit the strings on a 113 serve, much less make the return.
Today we’ll draw inspiration from the game of Cricket to break down one of the primary causes of this stark disparity in tennis return ability – vision.
A saccade is a rapid eye transition from one fixation to another. Focus on an object near you. Now, switch your focus to a different object. Congratulations – your eyes just performed a saccade.
In fact, your eyes have performed many small saccades while reading this article. Every few seconds as you read, your eyes perform a saccade from the words you are currently reading, to the next few words, and then do so again, and again.
Saccadic eye jumps are the most common method by which the gaze shifts. You perform at least 100,000 saccades every day.
Invisible Blind Spots
You are blind while your eyes perform a saccade. Since the image would be blurred and useless anyway, your brain simply turns off your vision while the saccade occurs.
Wait. What? It doesn’t feel like my vision is blinking in and out all the time.
That’s because your brain fills in the momentary blindness with a projected image. Usually, it’ll just take whatever image your saccade ended on and backfill your memory with that image.
Yes, your brain rewrites history to mask the momentary blindness. (This isn’t the only time on the court your brain will rewrite history.)
For everyday life, this is all well and good – I just looked from my book to my computer screen. I was blind for a few milliseconds during the saccade, but according to my memory, I was already looking at the computer for those few milliseconds, not blind. Does that falsity effect my life? Not at all… typically.
That changes when you’re playing a visually demanding sport.
Terribly Missed Returns
Your brain’s insidious cover-up of this mid-saccade blindness (known as “saccadic masking”) can create a lot of confusion while you’re on the tennis court.
Have you ever been so off on the serve return that you mishit nearly every return, and on most, you weren’t even close? This is most common in novel situations, say, the first set against a lefty, or against a player who hits with heavy kick.
You try to “watch the ball,” and you feel like you’re seeing it, sort of, and yet, somehow, you can never catch it on the strings cleanly.
What’s likely happening here is that your apparent vision on the ball is actually your brain backfilling the blind spot from your saccade. It’s fake. Your eyes are trying to catch up with the ball, and once they get there, late, your brain lies to your consciousness and displays that you’ve been seeing it the entire time. That’s why what you’re “seeing” isn’t assisting you with the swing – you’re not actually seeing the ball; the image you’re perceiving is just a projection during saccadic masking.
It’s possible you almost never see the bounce clearly on your return and don’t even know it. Most of the time, the serve is slow enough, and the bounce is predictable enough, that it doesn’t matter. Then, in a novel situation, that post bounce information becomes crucial to success, and because you’re blind when it’s revealed, you miss terribly.
With this in mind, we need to perform our saccades strategically to ensure we never miss the most important information of all: the immediate post-bounce trajectory.
Beat the Bounce
Cricket batsmen perform what’s known as a predictive saccade as the ball comes towards them. Their eyes jump from their first fixation, the release point, to their second fixation, the bounce area, before the ball is actually bouncing. The location for this predictive saccade is chosen based on visual information gathered from the ball’s early flight trajectory.
High level batsmen perform this predictive saccade earlier than low level batsmen. The better the batsmen, the more quickly they are able to identify the location of the bounce and jump their eyes there. The goal is to pick up the ball right before it hits the ground. The ball’s trajectory off the ground then determines the swing.
On fast bowls, low level batsmen aren’t able to predict the bounce early enough to fixate there before the ball arrives. This means they’re effectively blind to the bounce, and are denied the most important trajectory information necessary for the swing: how the ball comes off the ground. As a result, on sufficiently fast bowls, they miss almost every time.
Do Tennis Returners Beat the Bounce?
Watch a slow motion video of your favorite tennis player returning serve, and you’ll notice a behavior very similar to that of the high level cricket batsmen: the returner’s head moves to the bounce area before the ball gets there.
They track this way for the very reason discussed above. In order to actually see the bounce, you have to jump your eyes to its general location before the bounce actually happens. If, on the other hand, your saccade occurs with the bounce, rather than before it, you will be blind during the bounce.
In general, elite athletes in high speed sports predict a future point of interest using visual information available during the early part of an object’s flight. They then jump their fixation to that point of interest before the object gets there, ensuring the eyes have time to refocus on that new point before the object arrives.
Aren’t We Looking Away From the Ball?
The tennis serve moves too quickly for you to keep the ball on your fovia for the serve’s entire duration. As such, you must be content to fixate on only a few, critical points of interest, lest you attempt saccades which leave you blind during critical information reveals like the bounce.
If you predict the bounce location too early, though, you’ll lose sight of the ball for long enough that it’ll effect your swing. So what’s the most fault tolerant way to perform our predictive saccade? If we mess up the timing a little, we still want to succeed.
Try to pick up the ball right before it bounces. If your fixation is slightly before the bounce, your eyes will be able to track it the few degrees through the bounce without requiring a saccade.
If you’re a little late, most of the time you’ll still get to the bounce area before the bounce, and with your saccade completed, you’ll still see the bounce.
Eye Performance Takes Practice
Performing a predictive saccade to the bounce area will improve your serve return, but you won’t master it overnight.
Once you tell your brain “we’re trying to jump our eyes to the bounce,” your brain will begin to self correct. Every time you get that crystal clear image of the ball coming up off the ground, your brain will make a mental note that your timing was correct.
While you’re learning, you’ll often perform your saccade too early, or too late.
Too early, and you’ll mis-predict the bounce location, because your brain didn’t have enough pre-bounce flight information to guess it correctly. As a result, you won’t see the ball come off the ground clearly. Your eyes will perform a catch up saccade at some point after the bounce, and you’ll attempt your swing with very minimal post bounce visual information.
Too late, and you’ll saccade to the bounce area while the ball is bouncing, instead of before it bounces. Due to saccadic masking, you’ll be blind during the bounce, and by the time your eyes re-stabilize, you have already lost the most critical visual information available.
If you’re having trouble, try to say “bounce” the instant the ball lands. Not a moment sooner, not a moment later. This is very difficult to get exactly right unless you perform your saccade correctly. Predict the bounce location then jump your eyes to that area, and pick up the ball on its way into the ground. Do that, and you’ll get it right every time.
Idiopathic shanks on the serve return are probably a result of saccadic blindness – you can’t trust everything you “see.” Try to differentiate between the fake vision that your brain filled in after the fact, and the real vision that your brain was actually able to use when generating your swing.
Once you succeed in jumping your eyes to the bounce area before the ball, you’ll experience a sense of control over the return, especially against heavy spin servers, that seemed impossible before.