Overstable Vs. Understable: Understabilty for the Win?

Hey, fellow disc golfer! Disc golf terms can get a little confusing, especially to new players.

One of the most commonly asked questions beginner disc golfers ask is, “What are the differences between overstable and understable discs?”

The quick answers to overstable vs understable are-

  • An overstable disc will steadily travel to the left for the right-hand backhand players (RHBH) and to the right for the left-hand backhand (LHBH) disc golfers.
  • An understable disc will do the opposite. It will have a tendency to travel to the right for RHBH disc golfers and to the left for LHBH players.

That’s the basic explanation, but stopping there would be like parking your disc under the basic and missing a drop in birdie!

Let’s not do that!

What is Stability in Disc Golf? Overstable Vs Understable Vs Stable

I believe there is no need to overcomplicate disc stability; it’s how the disc flies as soon as it leaves your hand and as it slows down at the end of its flight.

That’s how it was explained to me when I first started playing many years ago, and it’s held true.

Disc golf frisbees are generally categorized into 3 categories, overstable, stable, and understable.


A disc with an overstable flight will have a tendency to drift left for RHBH players and right for LHBH disc golfers. How much it drifts left depends on just how overstable the disc is; yes, there are varying degrees of each category.

That’s why these terms can get confusing.


A stable disc has a straight flight path for RHBH and LHBH throwers. However, it can still have a slight fade or turn at the end of the flight.


A disc with an understandable flight will have a tendency to drift right for RHBH players and left for LHBH throwers.

Now that you’re beginning to get a grasp on overstable and understable flight paths, let’s move on to what has the greatest effect on the stability of discs.

What Affects Disc Stability?

The main reason I found it so difficult to grasp disc stability was because so many factors affect the stability of disc golf frisbees.

The design of the disc, how fast you throw it, the age of the disc, elevation, and wind all contribute to how stable a disc is going to be when you throw it.

Disc Design

Disc Stability begins at the manufacturer; they mold discs to fly a specific way by tweaking the weight, rim width, and height of the parting line.

Overstable disc characteristics include heavier discs, thicker rim widths, and higher parting line heights.

Understable disc characteristics include lighter discs, thinner rim widths, and lower parting line heights.

The type of plastic is another disc feature that contributes to the stability of the disc.

Arm Speed

How fast you throw and spin the disc also greatly affects disc stability.

Seasoned disc golfers often recommend more understable discs to beginners because they often lack the arm speed needed to get a high-speed distance driver to fly the way it was designed.

Overstable discs must be thrown at high speeds to generate the needed spin to fly correctly; otherwise, they fly hard to the left for a short distance and leave you very frustrated.

Understable discs require less speed; therefore, they fly much better for new disc golfers.

Disc Age

When I first started disc golfing, I heard other players talk about “beating in” a disc, so I took my discs to the boxing gym and started beating them up!

BUT that’s not what they were talking about…

When you hear other disc golfers talking about “beating in” the disc, they really mean how long they’ve played with that disc.

As you hit trees, rocks, and other hard surfaces, your disc’s flight will change because the shape of the disc has changed.

As you “beat in” a disc, it becomes more understandable because the parting line lowers each time you chip or grind off a little plastic.

The actual age of a disc doesn’t matter if it’s been sitting on a shelf and not being used.


Ask any disc golfer who’s traveled to play; your discs fly differently at various elevations.

At low elevations, discs are more understable, while at high elevations, discs are more overstable. Much like boiling water, this is all thanks to less air pressure as you head farther from sea level.

So if you plan on playing in the mountains, be sure to disc down and choose more understable discs.


Wind speed and direction have a drastic effect on your disc’s stability, and it’s often overlooked by beginners.

I can remember throwing into a headwind with an understable disc and watching it turn and crash hard to the right. I was incredibly confused because that disc usually had a slight turn to the right and then flew relatively straight.

What I soon learned was that a headwind is the equivalent of throwing faster, and a tailwind is the same as throwing slower.

Crazy physics talk!

Flight Ratings Explained

Check out this article for an in-depth look at disc golf flight numbers, as I’m only briefly going to touch on what they mean.


The speed number is the manufacturer’s best guess as to the amount of speed you need to get this disc to fly the way it intended.


The glide number is how well the disc will fly as it loses speed. Does it instantly drop out of the air (low glide), or does it float for a while before landing (high glide)?


The turn number indicates how understable the disc will be; if it’s a high number, then the disc is understable; if it’s low, the disc is stable to overstable.


The fade number is how much the manufacturer expects the disc to fly to the left at the end of the shot for RHBH disc golfers. Generally, a disc with lots of fade is overstable.

How to Choose the Right Disc for the Shot: Overstable vs Understable Discs

Choosing the right disc for the shot has drastically improved my game… Well, at least when I throw the shot I have pictured in my mind!

In all seriousness, knowing when to choose an overstable vs understable disc will shave strokes off of your score and keep you from losing discs to water hazards.

Overstable Disc Selection

What are the best times to choose an overstable disc?

  • When throwing into a headwind.
  • When you need to get way left on an RHBH throw or way right on an LHBH throw.
  • When playing at a lower elevation than you typically play at.

Understable Disc Selection

How about the best times to grab an understable disc?

  • When throwing with a tailwind.
  • When you need to drift right with an RHBH throw or drift left with an LHBH throw.
  • When you play a round at a higher elevation than you’re used to playing.

Frequently Asked Questions: Overstable vs Understable

Below, you’ll see that I’ve rounded up several commonly asked questions in reference to overstable vs understable.

How does the parting line height (PLH) determine stability?

The higher the parting line, the more overstable a disc will be, and the lower the parting line, the more understable a disc will be.

Does beating in a disc affect disc stability?

Yes, beating in a disc affects disc stability. The more beat-in a disc is, the more understable it becomes.

What is an understable disc?

An understable disc is a frisbee that drifts to the right for right-hand backhand throwers. The opposite is true for left-hand backhand throwers.

What is an overstable disc?

An overstable disc is a frisbee that drifts to the left for right-hand backhand throwers. The opposite is true for left-hand backhand throwers.

Final Putt: Understable Vs Overstable

Now that you know the difference between overstable vs understable, it’s time to put it into practice during your next round!

As I said, picking the right disc for the shot you’re about to throw will help shave strokes off of your game, and if it doesn’t, you can blame me, some random internet dude!

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