Towards a Taxonomy of Table Tennis Shots

Submitted by stephen on Wed, 03/08/2017 - 01:40

Beginning table tennis after a tennis career, I sought those identifying names for the basic set of shots that make up the game. In tennis we have serves, volleys, ground strokes, plus a few specialty shot types like overheads, half-volleys, and drop shots. With a few modifiers that’s about it. You can understand and play all phases of the game with just those few sensible, commonly used terms.

At first, playing table tennis seemed related. I learned about serves, pushes, and loops. I thought this was going to be quite manageable, but then there were chops, drops, touches, and fishes. Next there were smashes, flips, and flicks, fades, and hooks. Finally, when I heard shots described as “bananas” and “strawberries” I knew I was in trouble. Adding the modifiers I was lost: The pushes could be heavy or dead, the loops could be spinny, slow, or loop drives, the chops could be corkscrews or snakes.

When I read about Donn Olsen’s segregation of shot types into six categories in PATT – A Principles Approach to Table Tennis, I was inspired to consider developing a language to accurately describe all of the features available to players within the game of table tennis. His Shot Type Classification System begins with Serves, Control, Offensive Control, Offensive, Defensive, and Counter Attack shot types. Classes and sub-classes of distinct groups of shot types are contained within these categories.

The category of Serves is self-explanatory. Control refers to several classes of shot type whose primary intention is to avoid strong offensive responses – the “short game”. Offensive Control includes two classes of shot types which feature moderate and high topspin energy. Offensive shot types are those speed-oriented “loops”, “drives”, and “smashes”. The Defensive category reduces or uses speed and/or spin energy against the fastest shots in the game. Counter Attack involves high speed responses to high speed shots.

Recognizing the beginnings of a taxonomic system, I suggested to Donn that I might try to identify and describe all the circumstantial responses to the ball – the features – possible in the game based on his PATT frameworks. He seemed amused at the hubris of the enterprise but agreed to help, at least conceptually. I’ve never been short on ambition so I set about the process.

But the Shot Type Classification System groups shot attempts based largely upon their objective function within the game (thus serves, offense, defense etc.) but doesn’t always differentiate between the many subjective individual responses to specific circumstances a player must develop in order to play the game. As example, the only shot type PATT defines is the loop drive, a shot which can occur in both Offensive and Counter Attack categories, and is executed differently depending upon the spin type against which it is generated.

How can we identify those singular responses – what PATT calls “features” – the very specific skills players need to develop in response to given circumstances, in order to create shot outcomes? What makes each one unique within the feature set of a player?

The most obvious characteristic is whether the orientation of the shot attempt is forehand or backhand. So that is our first qualifier. It’s a forehand or a backhand. That was easy!

Unlike tennis, however very distinct racket angles and ball contact movements are required to manage the characteristics of each oncoming spin type. Against underspin we open the racket and contact the lower hemisphere of the ball, against topspin we close the racket and contact the upper hemisphere. Thus oncoming spin type affects the stroke mechanism, and each response has to be described and developed as a distinct feature.

So each shot will have to be qualified as being against one of the major spin typesunderspin, topspin or nospin. Okay, a forehand against underspin works pretty well.

But the ball speed and spin generated by a player’s stroke mechanism also define a shot as much as anything. Forehands which add topspin are nothing like those which create underspin. Those which use speed or spin in the oncoming shot differ from those whose primary intention is to add speed to the ball.

For this purpose PATT has described the perspective of energy management. We have four options with regard to ball speed and spin. We can use, add, reduce, or use and add either ball speed or spin or both.

Thus we will qualify our feature description by the primary intention of the shot. Is your intention to add spin, add speed, use or reduce oncoming ball speed or spin? Applying energy management to our developing taxonomic system we now might have, for example a forehand use and add topspin against underspin. Wordy, but pretty specific.

I mentioned the developing system to our club coach, Clyde, and he pointed out that contacting the ball over-the-table or off the table can make a huge difference to the mechanics of a shot, since the impediment of the table limits racket placement. They can clearly be different features.

To distinguish those two discrete circumstantial shot responses from our description we will then have to separate a forehand use and add topspin against underspin over-the-table, from a mechanically quite distinct feature of a forehand use and add topspin against long underspin (off the table).

I began to imagine the expanding taxonomic distinctions between similar features:

A speed-oriented shot like the one described might be called a forehand add speed against long underspin. For a slower shot focused on ball spin (a kind of “loop”) we might have a forehand moderate topspin against long underspin (the moderate designation uses one of PATT’s classes of lower speed Offensive Control shot types).

I was on my way to an encyclopedia of table tennis features!

Generating my first dozen or so descriptions, Donn pointed out that if I was to offer a thorough feature description I would need to include racket angles before, during, and after ball contact, the racket speed range required, the ball speed range created and responded to, speed/spin ratios, and even spin/spin ratios (the proportion of topspin or underspin to sidespin).

Ultimately, Donn and Clyde helped come up with four categories of information which might accurately describe an individual table tennis feature; the characteristics of the oncoming ball, the stroke mechanism, the energy management, and the resulting shot category.

Instead of a single line in my tome, now each feature required a full page!

Intrepid, I detailed descriptions of 30 or 40 of these features, while hundreds multiplied in my imagination like broomsticks in Disney’s Fantasia animation. Several weeks later I finally recognized the Pyrrhic (and humorous) nature of my efforts. Players don’t need a 500 page catalog of every possible shot in the game!

Donn once told me, “As a player you don’t need to know how to create every shot in the game, but you do need a response to all of them.”

My encyclopedia of features was not to be completed. But my quest had opened my eyes to a detailed examination of the complexity of our game. As convenient, colorful and amusing as shot names like “heavy chop” or “banana loop” might be, in order to think clearly and communicate the uniqueness of a feature in our rich sport, we need some detailed language, and a principles perspective.