Disc Golf Disc Numbers Explained Simply

1 comment by Denis Flaschner, Professional | PDGA #49081

Two pink disc golf disc numbers

Speed. Glide. Turn. Fade. Can you really boil down the nuance, the complexity, the pure beauty of a disc golf shot to those four flight characteristics? No. But it's the best we have. Today we're delving into the imperfect world of disc golf flight numbers.

Quick Note: You can check out our disc golf disc shop after your done; most of the discs in this article are available in our store.

The flight ratings are a reference tool that help us project how discs will fly. Unfortunately, manufacturers do not use a universal rating system. While there are some guides online that attempt to organize ratings across manufacturers, such as this one, there is no agreed-upon standard for rating discs.

In other words, these numbers are subjective and dependent upon individual power, skill, and throwing style. An advanced power player's understable turnover disc might be a beginner's overstable utility driver. Having a firm grasp of your own skill level is crucial to projecting how a disc will fly when it's in your hands.

But first we have to know what these numbers even mean. So let's delve into the cryptic world of disc golf numerology, and attempt to crack the code of disc golf flight numbers.

1. Speed

Speed Flight Number

A disc's speed rating represents how efficiently it cuts through the air and maintains velocity. When a disc leaves the hand it quickly reaches top speed and begins to slow down. Due to the sharpness of the edge and the weight distributed through the mold, some discs will slow down much sooner than others.

Slower discs are easier to throw with control and accuracy. If you happen to make a bad throw, a slower disc will not punish you as severely. Faster discs hold greater distance potential and, because they maintain velocity for so much longer, will zoom down low ceiling fairways, get bigger skips off the ground, and effectively cut through swirling winds.

More Speed ≠ More Distance

The history of casual disc golf is full of stories of beginners picking up a fast disc because it is marketed as a "maximum distance driver," only to be frustrated when it keeps crashing to the ground early.

It is vital for beginners to understand that more speed does not equal more distance. Perhaps it is best to think about a speed rating as a reflection of the minimum throwing power necessary for a disc to achieve its intended flight pattern.

For example, maybe you saw professional player Ezra Aderhold crush a 450ft hyzer with his signature Metallic Z Nuke, and now you want to give it a try. With a speed rating of 13, it is one of the fastest drivers on the market, and the Discraft description promises it will make long drives "as easy as pushing a button." Who doesn't want that?

Well, in order for the Nuke to get the slight -1 turn and extended 5 glide that give it such big distance, it must be thrown at the kind of elite speed that high level pros like Aderhold generate. For the average disc golfer, it will not get the turn and glide its flight numbers promise.

Rim Width and Speed

Rim Width of Two Pink Disc Golf Discs

For the most part, flight ratings do not correlate with a specific physical trait of a disc. The speed rating is the exception. For the most part, the wider a disc's rim, the higher the speed rating.

The maximum legal rim width is 2.5cm. It follows that many high speed discs on the market, such as the Innova Colossus or the MVP Limit, have the maximum 2.5cm rim width. The correlation of speed rating vs rim width roughly follows this pattern:

  • Speeds 10-14 = 2.1cm-2.5cm
  • Speeds 6-9 = 1.6cm-2.0cm
  • Speeds 2-5 = 1.0cm-1.5cm
  • Speed 1 = Less than 1.0cm

Wider rimmed discs are not only more aerodynamic, but they also have more weight concentrated on the perimeter of the disc. This heavier rim drastically increases speed and distance potential. It is also more difficult to wrap the hand around, and takes much more snap and spin to get up to cruising velocity.

Slower = Farther?

We all feel the need for speed. It's fun to throw discs fast. But for most players, maximum distance will be found when they find a happy medium between raw speed out of the hand and the extended glide that comes later in flight.

Discs like the Innova Leopard or the Kastaplast Falk combine a thin and easy to grip rim with generous turn and high glide ratings. These discs aren't slow, but they also aren't super fast. Most players will be able to unlock their potential.

If you're the type who likes scientific terms like "gyroscopic effect" and "moment of inertia", check out this informative video about disc speed from Best Disc Golf Discs.

 

 

2. Glide

Disc Golf Glide Number

The glide rating represents how well a disc will remain in the air as it slows down. If a disc is described as floaty, or having a lot of loft, this means it has a lot of glide. With a few exceptions, discs will have a glide rating of 2-6.

Since it occurs as the disc is slowing down, high glide discs are crucial to both gaining extra distance and controlling how a disc lands. Glidey discs are the straightest flyers, allowing for pinpoint accuracy through tight fairways.

The Glide Phase

While it is always listed as the second number in the four digit sequence, it's easier to think of glide as the third phase of the flight pattern. Put simply, a disc's journey can sequenced like this:

  1. Speed = immediate acceleration and maintained velocity
  2. Turn = high speed rotation and change of direction
  3. Glide = flight line maintained during deceleration
  4. Fade = low speed rotation and falling to the ground

Right out of the hand a disc will display its speed rating. While at high velocity it will then show off how it turns. Once it has made the turn and gradually loses speed, then the glide phase takes over. The more amount of time a disc spends in this phase, the higher the glide rating.

Projecting Glide

To better understand how to read a glide rating, let's compare two similar fairway drivers from Discmania, the FD and the FD2:

  • FD: 7 | 6 | -1 | 1
  • FD2: 7 | 4 | 0 | 2

With both being 7 speed drivers, most players will be able to get these discs up to the minimum speed necessary to get their intended flight. But where exactly do you see the FD's extra glide?

Let's pretend we are throwing both these discs at the same slight hyzer angle. Due to its -1 turn rating, the FD is going to take a slight turn to flat during the high speed part of the flight. Once it starts to slow down, it is going to maintain loft and glide on that flat angle for a long time before the slight 1 fade takes over.

Conversely, the FD2 has a 0 turn rating, so it will hold the slight hyzer angle of release through the high speed phase. Since it never comes off the original hyzer angle, it will quickly begin its descent to the ground during the glide portion of flight. The high 2 fade rating will make this descent even faster.

Because of its extra long glide phase, the FD is meant to be thrown on straight and anhyzer lines. Conversely, the FD2 performs best on hyzers, tight flex shots, and forced turnovers.

For a more scientific explanation for how discs achieve glide, check out this excellent video that delves into the physics of loft and other factors that effect glide:

 

 

3. Turn

Disc Golf Turn Number with arrow

Turn rating is a measure of how much the angle of a disc will rotate during the high speed phase of the flight. The turning action of a disc can be manipulated to find the unique shot shapes that only exist in disc golf. Matching a disc's turn to thread a winding wooded fairway is one of the most satisfying feelings in the game.

Turn is a major factor in describing whether a disc is overstable or understable. Discs with a lot of negative turn are flippy or understable, while discs with a 0 or 1 turn rating are overstable.

For example, the Axiom Paradox is a mid range with a -4 turn rating. This understable disc is very flippy, so it is naturally meant to be thrown on hyzer flips.

When released on a smooth hyzer angle, it will turn to flat and glide straight. Put some extra snap into it and the Paradox will turn from hyzer to anhyzer. When released with anhyzer, it will turn all the way over and dive into the ground for a roller shot. This makes the Paradox, and any disc with a -2 to -4 turn rating, great for hyzer flip shots.

Discs with a 0 turn rating will resist turn. The MVP Deflector is a mid range with a 0 turn rating. When released on a hyzer angle, it will hold and possibly increase that angle to nearly vertical. In order get any turn from an overstable disc like the Deflector, it will have to be released very hard on an anhyzer angle. Because it must be forced to turn, this shot shape is called a "forced turnover."

It's important to remember that the turn rating applies to the high speed portion of the flight. Like the glide rating, a thrower must put enough speed and spin into a shot to activate a disc's turn. A popular distance driver like the Innova Destroyer has a -1 turn rating, but in order to see that turn in action you will need a minimum amount of power to throw a 12 speed disc.

To turn a distance driver, beginners and lower power players will either need to choose a disc with extreme negative turn, such as the Innova Vulcan (13 speed, -4 turn), or drop down to a lower speed disc, such as a Innova Valkyrie (9 speed, -2 turn).

It's vital to have realistic understanding of your current power level to project how the turning action will apply to your game. For more detailed information about turn, here's another Best Disc Golf Discs video that breaks down the science behind this flight rating:

 

 

4. Fade

Sidewinder Disc Flight Numbers

The fade rating covers how a disc will behave as it slows down and falls to the ground. Fade ratings come in the 1-5 range. Discs with a high fade number are generally more overstable and have less turn and glide. On the other end, discs with a low fade number often have more turn and a high glide rating.

Controlling the fade is vital for pinpoint accuracy and low scores. Every inch matters, especially when approaching the basket, and choosing a disc with too little or too much fade can be the difference between a 10 foot tap-in and a 40 foot jump putt.

Fade = Predictability

Discs with a 3 or higher fade rating will always finish on hyzer. Throw it over an out of bounds area? It's coming back to the fairway on hyzer. Yank a late release and pull the disc off line? It's coming back on hyzer. Hurricane force winds? It's still finishing on hyzer.

In this way, the fade rating is a measure of predictability. The high fade disc is every disc golfer's security blanket, as you always know exactly what it is going to do. Popular overstable discs like the Innova Glow Firebird and Discraft Zone are beloved for their ultra predictable fade.

But that reliability comes at a cost: distance potential. Strong fade shortens the glide portion of the flight.

Finesse

Discs with a low fade rating will get softer landings with less horizontal movement. Throw them on a dead straight line, and they can finish flat on the ground with no fade whatsoever. These are best for finesse shots, such as a gentle turnover that has a subtle anhyzer drift all the way to the ground.

Low fade discs are especially important for players who only throw backhand or forehand, but not both. These discs make it possible to bend shots in either direction with the same throwing technique.

For example, let's say a right-handed backhand-dominant player walks up to a hole that demands a right turn for it's entire flight. They will need to pick a driver like the Legacy Patriot (1 fade) or a mid range like the Innova Halo Mako3 (0 fade) to ensure their backhand turnover shot doesn't pull hyzer and fade out early.

For more background on fade, we return again to the excellent video series from Best Disc Golf Discs.

 

 

Now Go Throw

We have only scratched the surface of the physics of disc golf flight. Other factors, like the weight of the disc, the plastic blend, and the amount of damage or "seasoning" a disc has absorbed will further complicate the flight characteristics.

The numbers are a helpful reference, but at the end of the day the best teacher is experience, and the best strategy is to go throw some discs and find out how the flight numbers apply to you.

If you are new to disc golf and want to get a solid disc, I would recommend starting with one of our stable midrange discs or understable fairway drivers as a starting point.


1 comment


  • Jon Andino

    This article does a great job of breaking it all down in an understandable way, without dumbing it down.


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