Overstable VS Understable Discs: An Ultimate Guide to Disc Stability

The ultimate disc golf success is hidden in understanding the fundamental nature of the disc. Your victory is hidden in how well you can visualize the behavior and flight pattern of the disc, even before it leaves your hand. Therefore, your ultimate guide to disc stability (understanding the disc golf overstable vs understable) is primarily going to focus on defining Disc stability as one of the basic aspects of the game.

For an impeccable game, it is necessary to know which type of disc should be used in which type of conditions, understanding disc stability is essential before you start building up your Disc Golf bag. Hitting the pin could be fun, however, the fun is spoiled if you keep losing round after round only because of missing a minor detail such as overstable and understable disc, flight and glide, and how you can hit the target every time just by flipping your wrist in a certain way. Here is a cursory look on what could be expected in an overstable, understable and stable disc.

Overstable Disc Golf Disc: Strong and powerful discs, more suited for headwind shots; preferred by veteran players.

Understable Disc Golf Disc: High-power, light weight discs; more preferred for beginners. These discs have a flat release with RHBH (Right-hand, back-hand) throw.

Stable Discs:  Discs with consistently neutral flight, follow a straight path when released.

Before we further discuss what overstable and understable discs are, and when you can use them to achieve optimum throw, let us have a look at some other factors. Disc stability, flight characters and flight numbers will help you choose an ideally perfect disc for your next game.

What is Disc Stability

Can you recall when was the first time that you threw the disc in the air? How did it move? Did it go straight or did it take a turn on the right hand side? Disc stability can be described as the way the disc moves through the air once you release it from your hand and the way it flies. Does your disc go straight in a line or it fades to the right or turns left?

Simply put, disc stability defines the relationship between the disc’s design and the way it flies.

Stability also defines the science behind the angular momentum and the trajectory of disc flight; i.e., how the disc maintains high-speed and glides through the air towards the pin. High-speed turn is the movement of the disc (left or right) when you release it from your hand. Stability defines how an object that is seemingly thrown straight diverts from its intended path. Along with high-speed turn, low-speed fade also decides how the disc will slow down and fades away either hitting the targeted pin or diving down to earth.

PLH and Beating-in: What Affects the Stability of a Disc

Before we start talking about “the disc has been beaten in”, a phrase often repeated on the course, let’s first know about Parting Line Height or PLH. It is the separation line on the nose of the disc formed during the process of disc preparation.  The process because of which PLH is formed is known as the dome-effect.

During manufacturing the plastic is poured into a mold and is allowed to cool. While the cooling process goes on, the edges of the plastic start to shrink. Depending on the type of the plastic the edges shrink to different degrees, some will stay relatively flat while others may shrink further, creating a dome-like effect on the surface of the disc, constructing a separation line right on the disc nose.

A higher PLH means that the plastic did not shrink too much and hence the disc will turn less, whereas, a smaller PLH means more shrinkage and greater turnover.

PLH and Beating-in of the Disc

After hitting trees, floor rocks and even the pin, your disc golf disc will get warped and will eventually change flight characteristics. Subsequently, frequent collisions with different objects will cause the disc to slightly damage and become more understable. The PLH of such discs gets pushed down and affects flight characteristics of the disc. While this might be frustrating for you at first, many seasoned players prefer their discs to be beaten up into a certain shape creating this sweet spot of their liking.

Disc Golf Overstable vs Understable: The Flight Characteristics of a Disc Golf Disc

stable disc golf disc in the air

The shape of the disc decides whether it will spin or maintain its straight motion. The front of the disc, which is also known as the nose, applies downward or upward force depending on the amount of air pressure above or below the disc. As the disc spins, the air pressure above or below the disc decides its flight characteristics.

The spinning and rotating movement of the disc creates momentum when you release it with high-speed. The faster the speed of the disc, the higher the spin generated, and consequently, the greater the stability will be. Hence, we can say that the faster the disc is spinning the more stable it will be. Apart from the air pressure, the shape of the disc and the speed, there are some other factors as well which can help you understand the movement of the disc.

Disc Flight Numbers: Know the Movement of the Disc Before You Throw It

It is a delightful feeling when the disc releases out of your hand; the sheer beauty of the shot and the complexity of the motion can, to some extent, be summarized with four flight characteristics:

1. Speed: It is the rate at which a disc will fly through the air. Currently, a 1 to 15 number rating system is used to define the speed of a disc. Faster discs require less effort to reach the target. Slower discs will require more power to be thrown through the wind. Slower discs are recommended for the beginners, whereas, experts can utilize more powerful discs to maneuver complex shots.

2. Glide: It is a disc’s ability to maintain launch-motion during the flight. Currently, 1 to 7 ratings are used to denote gliding characteristics of a disc golf disc. Discs with higher Glide numbers are recommended for new users. A disc with a bigger glide number will stay in air for longer periods of time.

3. Turn: High-speed turn is the tendency of a disc to either turn over to the left (Left Hand with a backhand style a.k.a LHBH) or to the right (Right hand with a backhand style a.k.a RHBH) during the initial part of the flight. High-Speed turn is currently ranked on a scale of +1 to -5. A disc with a +1 rating is more resistant to turning over, whereas, discs rated -3 to -5 are good rolling discs. For beginners discs with more turns are recommended, whereas, if you already have an established hand, you can go for the discs with less turn as they are more accurate to the wind pressure.

4. Fade: It can be defined as the opposite of the turn, hence, when you throw a Right-Handed backhand (RHBH), the disc will tend to move to the left and vice versa. Currently, the rating system of Fade is from 0 to 5, in which a disc with 0 rating has the straightest movement and a disc with a 5 rating will hook hard at the end of the flight.

An example of a flight number is given below:

3 | 3 | -1 | 2

The number shown above are in the order of Speed | Glide | Turn | Fade.

These four characteristics define how a disc intends to fly. Remember that each disc has a distinct and unique personality and the path that each disc takes can never be completely predicted. Another factor that must be considered is that each and every manufacturer has its own flight characteristics. The Disc flight ratings given by one manufacturer might not be useful for another manufacturer. Other factors impacting flight ratings include the mold and the model of the disc.

The Understable and Overstable Disc: What You Need to Know

The disc aerodynamics can get as academic as you want them to be. However, we will keep it simple and focused on the game side.

The study of the trajectory of the disc golf disc is quite an interesting one. When the disc leaves your hand, it is usually at its highest speed. During this high-speed phase, the rotational force and the higher air pressure on the rim of the disc tends to turn the disc towards its right-hand side (assuming that the thrower is using his right hand). During this phase, turn of the disc is directly proportional to its speed, assuming that there are no external factors influencing the flight of the disc such as strong or moderate winds. Now, as the disc starts to slow down the rotational forces no longer try to keep the disc moving towards right, hence, the disc slows down and moves to the left side and falls to the ground.

Disc golf understability vs overstability describe the motion of a disc and its overall flight pattern. It shows us the expected position of a disc when it is released and the position of the disc when it lands at the target.


An understable disc has a tendency to turn towards the right side (RHBH) when it is at the highest speed. Understable discs are lighter in weight with a higher glide rating. These discs might not serve well in windy conditions due to their light weight. Typically, understable discs have a turn rating of -2, -3, or -4. The fade of understable discs is usually smaller than overstable discs.

When to Use Understable Discs

Understable discs are great for beginners as they offer a lot of potential and are easier to throw. They can cover extra distance in less arm power and can maintain a straight narrow path once released from hand. The tendency to maintain a narrower path means they can cover added distance without turning. The utilization of understable discs should not be understated by earmarking them only for the beginners or for straight shots, understable discs can prove to be a lot more effective in a tricky position when you need to keep turning right without fading. Once you master the art of handling your understable disc, you will be able to play ace level anhyzers, hyzer flips and backhand rolls.

Let us have a look at when you should use your understable disc.

For a Long Flight

Understable discs are ideal for the conditions when you need a long drive and the air pressure around the disc is decreased due to tailwind. In such conditions an overstable disc will take a hard left turn while the understable disc will maintain its long flight.  

Turning Hyzer and Anhyzer

Understable discs when thrown with a hyzer can slowly roll into an anhyzer thereby turning to the left later on during the flight. This can prove to be a useful tool if you don’t have an effective forehand shot.

hyzer throw turning into an anhyzer due to understable disc

Hyzer and a Longer s-curve Trajectory

For a long-distance flight path, throw an understable disc on a hyzer angle and aim the disc slightly higher than the normal shot level. When you aim your shot at this angle it will allow the disc to slightly and gradually roll over while still maintaining the elevation. The shot covers full distance as the disc slowly stabilizes and then fades to the left. This is exactly the same way of shooting as is used for distance records; what is lost in accuracy is made up for in the covered distance.

Roller and Uphill Shot

Even though it is easier to format overstable discs into rollers, an understable disc will allow a longer air shot before the disc turns over and becomes a roller. By using the understable disc, you can be serving much more extended rollers as compared to other types of the discs. Similarly, throwing an understable disc in an uphill shot will provide a longer shot before the disc starts to fade.


These sturdy disc golf discs are generally preferred by veteran players as the disc will fade hard to the left sooner in its flight. Overstable discs usually have a high fade and small turn number.

When to Use Overstable Discs

Generally, overstable discs are utilized by intermediate and advanced level players. The discs require extra arm strength and can be maneuvered into fading to the left or right (depending on the player’s dominant throw). Experienced players use the extra power to dependably fade the disc into the direction that they want. These discs can beautifully shoot through the wind and play rollers, downhill shots, flex shots and some of the best and extraordinary overhand tomahawk throws.

The Overstable discs have a stronger grip in windy conditions and are more likely to fight the wind and maintain their flight pattern. They offer excellent control and can work nicely around the obstacles and corners to reach the target pin.

Here are the conditions when you should be reaching for the overstable discs.


Understable discs are preferred for tailwind throws as they can manage a killer turn even when the wind is not so much in favor. Owing to their tendency to turn at high speeds, overstable discs are ideal for throwing into the headwind. Throw a disc that is sufficiently overstable, it will still fight the turn and give you the straight shot that you are aiming for. If you chose a not-so-overstable disc for a headwind throw the chances are that it will turn right after release and instead of covering the intended shot it will fall on the ground nose first.

A Left Fading Flex Shot

An overstable disc is highly recommended for an anhyzer angle flex shot. A flex-shot is an intentionally thrown anhyzer-angled shot intended to achieve a little forced right turn assuming that the disc will eventually fight the anhyzer and finish to the left.

Straight Line Downhill Shot

An overstable disc resists any kind of turns and therefore can maintain a straight shot for a lot longer distance. When you are throwing a shot down a steep hill, your disc will maintain the high-speed for a longer period than a normal plain shot. In such cases an understable disc will take a sharp turn and miss the target. An overstable disc on the other hand will resist the turn and will take a stronger and straighter path.

Disc Golf Overstable vs Understable Forehand (flick) Shot

More stable discs are preferred by a lot of people for forehand flick shots. It is assumed that due to the increased torque (the force that rotates the disc), the speed will be transferred to the disc and the high-speed will increase sufficiently to support the shot right from the time of the release up to a lot longer on the route. However, this requires a lot of practice and at least a medium level of game expertise.  

Level Flight with a Hard Left Finish

 A straight route with a hard left finish is the ultimate overstable disc shot. When you are throwing an overstable disc golf disc for a hard left finish shot, you are pretty much utilizing the optimum usage of the disc.

Thumber Shot

Thumber, tomahawk or forehand shot can be thrown with an overstable disc to get a faster rotation and a narrower shot.

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