Overstable vs Understable Discs

When your buddy says they need a driver that’s “a little more stable,” do you know what they mean? In the world of disc golf, the term “stable” can be confusing, especially when it comes to overstable vs. understable discs. The truth is, the answer depends on the context.

For example, if they’re using a flippy disc like the I-Blend Sphinx and want something more stable, they’re likely looking for a more overstable disc. On the other hand, if they’re throwing an overstable disc like the Concrete Slab and want something less stable, they may want a more understable disc. The terminology around disc stability can sometimes be unclear, so let’s dive into the details to clarify.

What’s the Difference Between Overstable and Understable?

Disc golf uses a four-number flight rating system to describe a disc’s speed, glide, turn, and fade. These numbers are helpful, but they don’t tell the whole story. A disc’s stability is often discussed in terms of how much it resists turning right (for right-handed backhand throws) or how strongly it fades left at the end of its flight. Let’s break down what these terms really mean.

Overstable Discs: When and Why to Use Them

Overstable discs are designed to resist turning right at high speeds and fade left more sharply as they slow down. This makes them ideal for certain types of shots where you need more control and predictability. Overstable discs typically have a high fade number (usually 3 or 4) and a low turn number (often 0, -1, or even -2). Here are a few situations where an overstable disc shines:

1. Headwind Shots: When throwing into a headwind, overstable discs are perfect because they resist turning in the wind, keeping the shot more controlled.
2. Flex Shots: A flex shot starts with an anhyzer angle (right turn for right-handed players) but then “flexes” back to the left. Overstable discs make this move easier and more predictable.
3. Downhill Throws: Downhill shots maintain high speed for longer, which can make a less stable disc turn too much. An overstable disc will resist turning and give you the straight flight you need.
4. Straight with a Hard Left Finish: If you want a disc to fly straight before finishing hard to the left, you’ll want an overstable disc.
5. Forehand and Overhand Shots: Overstable discs are often favored for forehand (flick) and overhand (thumber or tomahawk) shots because they handle higher speeds and more torque, preventing them from turning too much.

Understable Discs: When and Why to Use Them

In contrast, understable disc golf discs have the opposite flight characteristics. They tend to turn right (for right-handed backhand throws) while still traveling at high speed. The amount they turn depends on their turn rating, which is usually between -2 and -4, with a smaller fade number. Here are some common scenarios where an understable disc is the right choice:

1. Tailwind Shots: Tailwinds reduce the relative speed of your disc, making an understable disc easier to throw. It’s a great choice for long-distance shots with a tailwind.
2. Late Right Turn: Throwing an understable disc with a slight hyzer angle can create a rightward turn later in the flight. This can be useful when you need a disc to turn without flipping too much at the start.
3. Rollers: While both stable and overstable discs can be used for roller shots, an understable disc is much easier to work with, as it will flip into the ground with less effort and cover great distance.
4. Uphill Throws: Uphill shots require more energy to reach the target, causing the disc to fade earlier. An understable disc will stay in the air longer, helping you get more distance before it starts to fade.
5. Giant S-Curve: For maximum distance, throw an understable disc on a hyzer angle with a slight upward aim. The disc will gradually roll over, ascend, stabilize, and fade left. This is a classic distance throw, though accuracy may suffer.
6. Headwind vs. Tailwind: In a headwind, an overstable disc fights the wind better, while an understable disc will turn more. In a tailwind, the opposite happens — an understable disc will hold its line longer, while an overstable disc will fade quicker.

Examples of Overstable and Understable Discs

Overstable Discs:

• Concrete Slab (12, 3, 0, 4)
• Scepter (9, 4, 0, 4)

Understable Discs:

• Maya (12, 5, -3, 1)
• Sphinx (9, 6, -3, 1)
• Kon Tiki (4, 5, -3, 0)

Why You Need Both

In disc golf, having a variety of disc golf discs with different stabilities is like having a toolbox for different situations. Whether you’re facing a headwind, a tailwind, or need to shape a specific shot, understanding when to use an overstable or understable disc is crucial. The right disc for the job can help you make more accurate throws and improve your performance on the course.