Speed, lift, turn, fade: what the four numbers mean—and why “speed” does NOT mean “distance.”
You flip a disc over and see four numbers: 9 · 5 · −2 · 1. This is the language of disc golf—and once you understand it, choosing a disc becomes a no-brainer.
Here’s what each number really means—and, most importantly, the common misunderstanding that costs beginners the most.
The 4 numbers, always in the same order
The order never changes, regardless of the brand. Discraft puts it this way: “ The order of the numbers is always constant.”
Speed → Glide → Turn → Fade
| Number | Range | Can it be negative? |
|---|---|---|
| Speed | 1 to 14 | No |
| Glide | 1 to 7 | No |
| Turn | +1 to −5 | Yes — the only one |
| Fade | 0 to 5 | No — never |
These ranges are identical for Innova and Discraft—there are no discrepancies among my sources.
Two important points to keep in mind right away:
- Turn is the only value that can be negative. A turn of +1 resists turning the most; −5 turns the most.
- Fade never goes below 0. A disc cannot have a “negative fade”—that’s what turn is for.
1. Speed: The Number One Misconception
Speed is NOT distance. This is the most common mistake in the sport, and it causes thousands of beginners to buy the wrong disc.
Innova’s exact definition: “the speed at which a disc can travel through the air ”—that is, the arm speed required for the disc to fly as intended.
In practical terms: a high number = a wider, more aerodynamic rim. It takes power to “activate” this profile.
What happens to a beginner with a Speed 13: the disc doesn’t activate. It behaves more overstable than expected, dives left early, and crashes. A Speed 6 will fly farther in their hands than a Speed 13. This is counterintuitive, and you can verify it on your very first outing.
What speed is best for a beginner?
There’s no consensus—and it’s better to be honest about that than to make up a number:
| Source | Recommendation |
|---|---|
| Innova (manufacturer) | No specific number. Only: “Fast discs are generally not recommended for beginners, as they require more power to fly properly” |
| Discraft (manufacturer) | No specific number on its beginner page |
| Infinite Discs | Speed 1 to 5 (the most conservative) |
| Some scales | Maximum ~8 |
Reasonable range: don’t exceed speed ~7–9 at first, and start even lower (putters and midranges, speed 2–5) to learn the basics. The discrepancy between Infinite (1–5) and the broader scales (max 8) is real—the industry hasn’t agreed on a single number.
2. Glide: 1 to 7
Innova’s definition: “the disc’s ability to maintain lift during flight.”
- High glide = the disc stays in the air longer → helps with distance. Excellent for beginners.
- Low glide = the disc “falls” faster → performs better in the wind and is easier to control.
For a beginner looking for distance without power, high glide is your best ally.
3. Turn: +1 to −5
Innova’s definition: “a disc’s tendency to turn or bank to the right (for a right-handed backhand throw) during the initial portion of flight”.
This is the first half of the flight, when the disc is traveling fast.
- Turn of 0 or +1: The disc resists; it doesn’t turn to the right. Requires power.
- Turn of −3 to −5: The disc readily turns to the right.
⚠️ All directions assume a right-handed backhand (RHBH) thrower. For a left-handed thrower, or for a forehand throw, the directions are reversed.
Innova’s recommendation for beginners: “Discs rated −2 to −5 tend to be easier to throw and achieve a full flight.” In other words, understable discs.
4. Fade: 0 to 5
Innova’s definition: “the disc’s tendency to hook to the left (for a right-handed backhand thrower) at the end of its flight.”
This is the end of the flight, when the disc slows down. All discs fade as they slow down—it’s physics, not a defect.
- Fade 0: Finishes straightest.
- Fade 5: hooks sharply to the left at the end.
The caveat that almost no one mentions
Innova states it in black and white: “Glide, turn, and fade ratings should only be compared among discs with the same speed rating. ”
Comparing the glide of a Speed 12 to that of a Speed 4 makes no sense in this system. The number 5 doesn’t mean the same thing at two different speeds.
Stability: How to Interpret It
Stability is not a number in the Innova 4-digit system. It is derived from the combination of turn and fade:
| Stability | Turn | Fade | Behavior | Example |
|---|---|---|---|---|
| Overstable | 0 to +1 | 3 to 5 | Resists turning, hooks sharply to the left | 0 / 4 |
| Stable | low | low | Flies straight | −1 / 1 |
| Understable | −3 to −5 | 0 to 1 | Drifts to the right, doesn’t come back much | −4 / 1 |
Innova is clear about overstable discs: “They are usually thrown by powerful players and are not suitable for beginners.”
Crucial distinction: stability is a property of the disc. The hyzer/anhyzer is a property of the throw. The two are independent and combine. See [how to throw a disc](/guides/throwing-a-disc-in-disc golf).
Discraft’s 5th Digit
Discraft publishes a fifth “stability” value, expressed as a decimal, ranging from −3 to +3. Real-world example: the Discraft Nuke: Speed 13 · Glide 5 · Turn −1 · Fade 3 · Stability 1.6.
- 0 = stable
- Negative = understable (−1 mild turn, −3 severe turn)
- Positive = overstable (1 subtle fade, 2.5 hard fade)
There’s a common approximation (stability ≈ turn + fade), but it’s not quite right: the Nuke would be −1 + 3 = 2, whereas Discraft lists it as 1.6. Use this as a rough guide, not as a formula.
A Word of Honesty: These Numbers Are Not an Exact Science
This is important, and few articles mention it:
Flight numbers are neither regulated nor scientific. There is no PDGA standard governing them—the PDGA regulates the physical dimensions of discs, not their flight numbers. These are ratings assigned by each manufacturer, with no oversight body.
Reputable sources are categorical: the flight numbers are “not based on any precise calculations,” are “neither regulated nor derived from rigorous scientific testing,” and even: “Discs from the same brand with the same flight numbers, in the same weight class and made of the same plastic, can sometimes fly in radically different ways.”
Innova also acknowledges this: “Flight numbers are guidelines, not exact predictions.”
What this means for you: two discs from different brands with the same 9/5/−2/1 flight numbers won’t necessarily fly the same way. Use the numbers as a guide, not as a guarantee.
Where did this system come from?
The four-digit system was developed by Dave Dunipace, co-founder of Innova. It is said to have been finalized in 2001 and published in the 2002 Innova catalog—a date I have not been able to confirm with Innova.
Other brands adopted it de facto due to Innova’s popularity, but without any obligation or standardization. This explains the differences between manufacturers.
How to Choose Based on the Numbers
For a beginner, the ideal profile:
- Low speed (2–6 for learning, up to ~7–9 afterward)
- High glide (5–7) — for distance without power
- Negative turn (−2 to −5) — Innova explicitly recommends this
- Low fade (0–2) — for a more predictable landing
Example of a typical beginner’s profile: 5 · 6 · −3 · 1.
And remember the order of purchase: midrange first, putter next, driver last. See [which discs to choose as a beginner](/guides/choosing-discs-for-beginner-disc golf).
Frequently Asked Questions
What do the numbers on a disc mean?
In order: speed, glide, turn, fade. Example: 9/5/−2/1 = speed 9, glide 5, turn −2, fade 1.
Does a high speed number mean the disc will fly farther?
No. It refers to the required arm speed. A speed 13 disc in a beginner’s hands will fly shorter than a speed 6 disc.
Which is the only rating that can be negative?
Turn, ranging from +1 to −5. Fade never goes below 0.
Are the ratings the same across different brands?
The ranges are the same (1–14, 1–7, +1 to −5, 0–5), but the ratings are neither standardized nor scientifically tested. Two discs that look identical on paper may fly differently.
Do the directions apply to left-handers?
No. Everything is described for a right-handed backhand throw. For a left-hander—or a forehand throw—the left/right directions are reversed.
This guide is part of our disc golf series:
- 🏆 [How to Play Disc Golf: The Complete Guide](/guides/how-to-play-disc golf)
- [How to Throw a Disc](/guides/throwing-a-disc-in-disc golf)
- Which discs to choose as a beginner
- [Find a course near you](/disc golf) — 69 courses in Quebec
