How to Apply the Concept of Chunking in Tennis
This is a sample of a lesson from my flagship online tennis resource - Beyond the Swing: The Course.
In this lesson, we’re not only going to tackle how to prepare your racquet, we’ll also briefly discuss what’s called the ‘unit turn’ - along with some thoughts on ‘technical’ training. But first, let’s define chunking as this concept (which you may have heard of before) can be a secret weapon when aiming to improve ‘technique’. It’s the simplest way I have found to group together many requisite positions in various tennis strokes.
Chunking Defined
Chunking has gained popularity of late - and for good reason. It’s a type of learning strategy where the aim is to literally ‘chunk’ many movements or information together, to make execution or memory recall easier.
Think about trying to remember a series of numbers. To better remember the digits, instead of saying 7-6-8-4 (seven, six, eight, four) we could say 76-84 (seventy six, eighty four) - the latter making it seem like there are only 2 numbers instead of 4. Chunking the numbers together makes it easier to remember them.
When learning a complex motor skill - like hitting a backhand - it’s also easier to ‘chunk’ several movements together, rather than focusing on every single body part (and where it needs to be, and at various points of the swing, etc). The reality is, there are simply too many moving parts. Nobody is capable of thinking about turning their shoulder, keeping their elbow out, getting their racquet tip to face up, keeping a wide base, with the weight on one leg and so on and so forth - and all at the same time.
You see, what we need to do is use one cue or thought to enable us to group many movements together - effectively, turning it into one movement. At the very least, from the player’s perspective, there should be one clear mental representation of what should be done.
Now, chunking also works well because of retention. We’re able to retain more of what we’ve learned. Here’s how it works. A trigger is first needed to stimulate one of our senses (sight; sound; touch; smell; taste). This information from our senses is then directed to the short term sensory memory store which has a limited capacity of 5-9 items (or chunks) of information, plus or minus two.
Once in the sensory memory store (STSS), information is stored for up to one second. During this time the relevant information we need is filtered from the irrelevant – this filtering process is known as ‘selective attention’.
Here’s what happens when information gets passed to our STM (ALTIS):
“The relevant information is then transferred to our short term memory (STM) where a limited capacity of information can be stored for up to a minute (unless intentional rehearsal is performed to allow us to retain it for longer). Information in the STM allows us to make decisions; a process which can be expedited if information from the long term memory (LTM) is compared against this new information and associations are made. Relevant information is then once again filtered to the next stage into the LTM.”
The key here is intentional rehearsal. When we provide our brains with relevant information, based on the sensory input (what we’re perceiving in our environment - in front of us), we’ll make better decisions and our ‘circuits’, will continuously be updating. That’s how chunking unfolds - effectively, “we ‘chunk’ files in the brain to make detection, analysis, problem solving and solutions a bit easier to access and utilize” (Pfaff 2020).
Let’s now apply this to some technique work in tennis.
The Unit Turn
The unit turn is defined as the rotating of the upper body (primarily the shoulders and trunk), in preparation for the upcoming strike of the ball. Let’s use the forehand as an example - the unit turn for this stroke not only facilitates a turning of the trunk and shoulders, it will concomitantly get the racquet back as well.
Obviously, we want to turn because it will help us impart more velocity on the racquet (when we uncoil and accelerate the swing) - which will then impart more velocity on the ball. If we were just to take the arm back (like many beginners do), we would not have the ability to hit with lots of pace. And if we did try to hit with more pace, we’d likely make errors (because the movement of smaller body parts - like the arm or hand - have more perturbations and degrees of freedom, compared to larger body parts - like the trunk)
The beauty of the term is that we think of the entire ‘unit’ turning. Whether coaches who coined the term knew it or not, this is a chunking strategy. In other words, we’re not thinking about the shoulder, the arm, the elbow and/or any other part of the body in isolation (although we might...but more on that below). We’re thinking of the entire body (specifically, the upper-body) as one whole part. The cue, then, would be ‘turn’ - as soon as we know which stroke we’ll be hitting - and that would lead to the entire upper-body turning to prep for the shot (image below).
Forehand ‘unit turn’ - Marc Polmans.
Racquet Prep
I want to briefly distinguish between racquet prep and the unit turn. With the unit turn, our focus is on rotating our trunk and shoulders (those are the major areas) to facilitate a better preparation to the oncoming ball.
But we can encounter 2 issues if we don’t also focus on the racquet.
First, even if we perform a unit turn, it doesn’t tell us a lot about the racquet. Where should it be located? Left to their own devices, many might prepare with the racquet straight back (and some older generation players, still do).
There are obviously many variations that exist when it comes to the preparation of the racquet - just look at the images below:
Polmans BH racquet is more ‘upright’ during preparation.
My racquet on the BH is more ‘tilted’ during the prep.
There are many reasons for this - some have to do with grip, some have to do with muscle and joint architecture (do you have long levers, or short ones) and most are a result of motor programs that have been built from years of playing.
You can see that trying to fit every single player into the same ‘model’ is a very narrow approach. It’s likely detrimental as it in no way accounts for individual differences.
That said, we do want the racquet to go through a circular type of action on groundstrokes. There are many benefits to this but the primary one is that it can impart more momentum (both angular and linear) on the ball. That is, if our impact is appropriate (check lessons 3 and 4).
As renowned coach Louis Cayer has said about the forehand, for instance;
“When preparing, the racquet should be out to the side a bit and slightly angled (this will help to throw the racquet at the ball and create greater racquet head speed)”.
Here are a couple examples of the forehand:
Federer has a racquet prep that is more ‘tilted’. The strings are facing slightly downwards.
Serena has a racquet prep that is more upright (tip of the racquet facing straight up.
As you can see, there are slight variations but the commonalities are (from my perspective):
Racquet starts slightly out to the side
Racquet tip is facing upwards (some more vertical while some more angled)
Racquet face is slightly tilted downwards (some do it more, some less - or in the case of Serena, not at all)
Take Action
Drill - Early Racquet Prep
In this drill, the aim is to prep the racquet (and unit turn) as early as possible. The player needs to be aware ahead of time, what ‘prep’ means. For this player, the aim was to turn and have the racquet ready before the ball crossed his side of the court. Even if he doesn’t accomplish this aim, having it as a focus/cue (more on cues in module 1), will undoubtedly get him prepping sooner.