The Physics of Spin — SS #25

Topspin, slice, underspin!

If you’re striving to be a competent tennis player, you need to be able to control the ball and place spin on it. So in today’s issue, we’re going to dive into the two main types of spin that you should be able to impart on a ball, the pros and cons, and when you should use each type to your advantage.

And to do so we are going to use two resources. The first is Vic Braden’s Tennis 2000, which, as I’ve mentioned before, is something of a tennis bible to me.

And we’ll also add some tidbits from one of Braden’s other books, Mental Tennis: How to Psych Yourself to a Winning Game. (Thank you again to one of my students who gifted me this book!)

I’ll also mix in some of my commentary to add some color.

Underspin—Not Slice

Let’s start with definitions.

When you hit what is considered a “slice” on a groundstroke, the ball is actually spinning backward. This, by definition, is called underspin—not slice. I know that I’m being a bit pedantic with definitions here, but I believe that we should use the most appropriate language at all times and also describe phenomena as best as we can.

Pros of Underspin

Underspin is useful in a couple scenarios.

The first is that if you’re getting tired, it generally takes a little less out of your body to hit your groundstrokes with underspin. So if you find yourself in a long, drawn-out match, don’t be afraid to use underspin to help you take some air and reduce the strain on your body.

In Mental Tennis, Braden writes that one should use underspin for steadiness and to pace yourself. Noting that, “[U]nderspin offers a nice way to hit steady, conservative deep shots.”

He also writes that underspin can be used to change the pace of the ball as it, “[A]llows you to take speed off the ball.” pg. 172.

The second is that the ball you hit travels slower through the air. This can further be broken down in two different ways.

• The first is to defend. We’ve all seen players like Steffi Graf, Roger Federer, or today, names like Dan Evans and Grigor Dimitrov, use their underspin to slow down the ball and float it deep into the court. If you have an opponent who refuses to come to the net against you… just use underspin again and again every time you need time to recover.

• The second is to approach the net to get into a better volleying position. Remember that the closer you get to the net, the more your potential angle increases. So taking speed off the ball actually allows you a little more time to sneak in closer. Here, though, you have to be on the lookout for what your opponent is going to do. Drive? Or lob?

Cons of Underspin

While hitting underspin has some benefits, there are actually more issues than benefits. You don’t have to take my word for it— here’s what Braden had to say in Tennis 2000:

“Only talented players can hit the shot well with any consistency, and then only through experience, practice, and concentration. The reason for this, physicists tell me, is that the minute you begin to favor underspin, by bringing your racket from high to low, you not only must make corrections with your wrist/forearm, you must manipulate five variables: 1) the speed of your opponent’s shot, 2) the ball rotation that your opponent has hit, 3) the angle at which you must come down on your swing, 4) the range at which you must bevel your racket, and 5) the speed at which you must swing down with that beveled racket. Little wonder that people have a tendency to lose control on underspin.” pg. 32

My understanding of all of this is that underspin takes a lot more calculations than topspin to consistently hit well. Not only that, but you’re relying on gravity in effect to help you to bring that ball into the court. It is so so easy for you to float that ball long when someone is applying pressure on a particular wing.

Now imagine if you can only hit underspin on a particular groundstroke… your options for passing someone are also limited. Sure, once in a while you might pull off a TV-style passing shot down the line. But more than often you’re going to float the ball. The common retort I get here is that, “well it’s a lot tougher to volley a slice.”

Maybe.

But once you start moving up levels, any competent player will start eating up that floating slice.

Tennis in that way is confusing. The hacker thinks that the slice is an amazing shot because the group of opponents that he plays against don’t have the net skills to take advantage of his pathetic floaters.

As soon as he moves up a few levels, he’s toast, though.

In my freshman year of college, I was invited to play a match against a club hacker. I don’t mean this in a derogatory term by the way. But he had beaten a few others on the team by simply floating the ball back into the court again and again with deep underspin shots on both sides.

Luckily, someone had told me that this was how he played. So all I did, from the very first serve, was to serve and volley to his backhand side and close in on the net at every chance that I could.

I could tell that he was not happy when we shook hands and had probably expected to get a win under his belt that day.

Topspin

You should be able to generate topspin off both wings if you want to play at higher and higher levels. In physics, when topspin is applied to a tennis ball, the Magnus effect works upon it to pull it downwards. (I believe this also applies to underpin but in the opposite way).

Here’s what Braden highlighted about topspin:

“On the other hand, if you just concentrate on hitting […] with topspin—by swinging from low to high with a fixed wrist—you can hit the ball almost as hard as you want and still be safe. No matter what your opponent hits, or what pressure you’re under, you can take his shot and return it with topspin. Instead of five variables, you only have three.” pg. 33.

Another way of putting this is that topspin requires fewer calculations to get the ball consistently into the court. Not only that, but because that ball is spinning forward, it’s more likely to drop into the court.

When it matters, most, when you’re tight and tense, or it’s a break point, I know which kind of spin I’d want to be imparting on the ball.

What about you?

Additionally, Braden also adds: “Topspin is the only stroke in tennis that allows you to slug away and get rid of frustrations without worrying about losing the ball. I’ve noticed over the years that many people tend to choke because they can’t hit the ball hard. They’re naturally strong, or frustrated, and they want to hit all-out on the ball, but if they’ve learned an underspin game, they aren’t allowed to do this; they have to baby the ball. You rarely have to finesse topspin.” pg. 34.

Pros of Topspin

To summarize, with topspin:

• You have fewer calculations

• You don’t have to worry about feeling the ball into the court under passing pressure or stress

• The Magnus effect works in your favor and you can swing almost as hard as you want if you get the racket sufficiently low

What’s there to not like?

I’ll leave you with this from Braden.

“Remember that tennis is a lifting game, and to hit groundstrokes hard—with the greatest depth and safety—it will be in your best interest to build your game around topspin.” pg. 30.

Cons of Topspin

That being said, nothing is perfect!

Probably the one downside of topspin is that you can’t half-ass it the way you can half-ass underspin. If you’re getting tired, you still need to move and recruit your body into the appropriate positions to get the racket head below the point of intended impact and swing away and up toward the target.

Develop Your Game

Being able to generate consistent topspin off both wings is one of the keys to playing at a higher level. By being able to use topspin on both groundstrokes, you’ll be able to swing fast and still get the ball to land inside the bounds of the court (more often than not). But that doesn’t mean the underspin is useless. I recommend having it in your repertoire!

Curious to see how all this applies to your game? Book a free 15-minute intro session with me. It’s not a sales call, just a chance to see how my coaching works and whether we’re a good fit. Ready to improve? Let’s chat!

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