Disc Golf Flight Ratings Explained
Updated: Jun 28, 2020
For beginners at disc golf, the 4-number flight rating system invented by Innova seems very cryptic – and that’s for a good reason – it is! This is an in-depth topic, with each rating number requiring detailed explanation, and so this page addresses the issue at an increasing level of complexity as it goes along.
The Flight Rating system currently has the following names and ranges:
Speed - with ratings from 1 to 15
Glide – with ratings from 1 to 7
Turn – with ratings from 1 to -6
Fade – with ratings from 0 to 5
The numbers and ranges are arbitrary.
Not all makers use this system, with MVP and Discraft having their own, silly systems. :P However, the disc golf community always rates discs according to the Innova system, as can be found at websites such as Flight Analyzer, http://www.flightanalyzer.com (right)
Understanding the Jargon: Hyzer and Anhyzer
Hyzer is the angle you release the disc on, relative to flat. Most disc golf throws require the disc be thrown close to flat.
Even small changes to the hyzer or anhyzer angle have a large impact on the flight shape the disc will make. Each disc behaves differently in the air depending on its flight rating, airspeed, spinning speed, nose angle and hyzer angle.
How does the Innova Flight Ratings system work?
The numbers indicate the expected flight shape, when thrown on flat ground, in calm air, on a flat, straight line, with a Right-Hand Backhand throw, using the power the speed rating of the disc requires.
It does NOT indicate the flight shape beginners will be able to make using them unless the discs are rated speed 3 or below, and they have decent form.
Addressing each of the numbers in the simplest way
Speed
In the most general terms, a higher Speed rating means a thicker (wider) rim, or wing.
The Speed rating does not relate to how fast the disc will fly, as is often thought. It indicates (roughly!) how fast a disc NEEDS to fly, in order to make its proper flight shape. The “proper flight shape” is described by the disc’s numbers.
It is therefore not possible for a new player to make drivers fly correctly – and indeed newbies should not throw any disc rated faster than 6 for the first few months of their disc golf career, at least.
Speed 10 discs and above are for competent players of the game, and speed 13, 14 and 15 discs are basically for experts only. For newbies, this isn’t some “oh yeah, that applies to everyone except me” rule. If you are new and throw high-speed drivers they will ruin your game.
Disc Speed ranges in their categories:
Putters are Speed 1 to 3
Midranges are Speed 4 to 6
Fairway drivers are Speed 7 to 9
Distance drivers are Speed 10+
Glide
Glide is a simple one. A low number indicates a disc which will not fly far. Higher numbers mean a disc will fly far. Much effort is required to make low glide discs fly far, while minimal effort is required to throw high glide discs far.
It is therefore much easier to judge where a low glide disc will land, than a high glide disc. There is no free lunch in disc golf, sorry!
A disc like the amazing Latitude64 Sinus has the flight rating 2 1 0 3. That means it glides like a brick and crashes into the ground after a short flight. The Latitude64 River has the flight rating 7 7 -2 1 and likes to fly past your planned landing zone and just keep on going.
Turn
Turn is the tendency of some discs to “flip up”, “flip over” or “turn over”. This characteristic is known as being understable. If you throw a disc on a hyzer angle, and it flips up to flat, or flips over and glides to the right, on an anhyzer angle, then the disc is said to have “turned”. (See Figure 2. above)
Any disc that reduces its hyzer angle at any point in its flight has “turned”, even if only a little. “Flip” and “turn” are used interchangeably. Often, you will see the phrase "Turn" referred to as "High Speed Turn", or the acronym "HST". This is because Turn only takes place during the high speed portion of flight.
There are three basic disc types:
Stable = flies straight then eventually fades gently to the left
Understable = turns to the right, before fading to the left
Overstable = fades early and hard to the left
New players need to start out with understable discs, using only putters and midrange discs initially.
Fade
Is what all discs do at the end of their flight if given enough altitude. For a right-hand backhand (RHBH) throw and a left-hand forehand (LHFH), all discs will fade to the left at the end. Both throws produce a disc turning clockwise as viewed from above.
For left-handed backhand (LHBH) and right-handed forehand (RHFH) throws, discs will always fade right. Both throws produce discs which turn counter-clockwise.
Fade is caused by gyroscopic precession and reduction of airspeed shifting the center of lift. The disc’s spin speed and forward velocity reduces due to drag.
The forehand throw, which spins the disc in the opposite direction, results in fade opposite to the backhand throw – and this is why all players should learn to throw a forehand with their dominant arm or to learn to throw backhand with their off arm.
Just how MUCH a disc fades is indicated by the numbers, with 0 being no fade (very rare, and it will still fade if thrown with sufficient altitude) and 5 being massive fade to the extreme left of the thrown line.
Consistency of Flight Ratings between companies
Because the Innova System has no objective test which produces the Flight Rating numbers, there is no way for manufacturers to have consistent Flight ratings between them.
For example, a “Speed 14” driver from Latitude 64 is more like a “Speed 12” or “Speed 13” driver from Innova.
Glide and Turn are difficult numbers to nail down, due to the wide range of airspeeds discs travel at when used by different abilities of player.
This can make it difficult for beginners to properly choose discs based purely on Flight Ratings. It is wise to take expert advice on disc purchases until you are able to properly identify your needs, and purchase accordingly.
This is why Vortica Disc Golf has a standing offer to replace any disc we personally recommend for a player if it does not perform for them, as we said it would.
More, On Speed!
Speed is a poor name for the first rating number, as it does not tell you how fast or far a disc will go, but rather, how wide the “wing” of a disc is. The wing or rim is the outer portion of the disc – the part you grip. The inner part of the disc is known as the Flight Plate.
The rim width or wing size indicates the Speed rating – but there is little agreement about how many millimetres of wing each speed rating relates to, and hence some variance between manufacturers.
This is a very unsatisfactory state of affairs for consumers. It would make much more sense to simply change the “Speed” to “Wing” and rate it to the closest millimetre. So, discs would have a Wing rating from about 6 to 25, in mm. Ah well, I can dream...
What is the highest Speed disc possible?
The total distance between the distal and medial finger joints of the index finger is what defines the widest rim disc a person can usually grip properly. (See below) For most people, this will mean a wing size of 25 mm is about the maximum size.
Wider rims are possible, but only very long-fingered people would be able to grip them correctly, and they would not have wide appeal. The PDGA limit wing size to 26mm, and although there have been three moulds approved at 26mm in the past, they were not successful.
How to make a proper Power Grip
The crease of the distal joint (the last one) of the index finger must fully engage with the bottom edge of the rim of the disc, and the index finger knuckle must be above the Parting Line. Watch the video below.
This is the definitive Power Grip guide, by Mike C,
who has other excellent tutorial videos on his YouTube Channel.
Moron Speed! Err – I mean “Why Noobs Shouldn’t Use High-Speed Discs!”
High-speed drivers deviate from their thrown line more than any other kind of disc. Conversely, putters are the most accurate disc in your bag and deviate from their thrown line very little.
For any given throw, a player should use the lowest speed disc they possibly can, and that is why professional and expert players often throw putters from the teepad.
New players are unable to accelerate high-speed discs to the speed at which they will fly their intended flight path. This results in players throwing very short anhyzer throws with an exaggerated “S” shape. Doing so will mess up a player's form for years, and prevent them advancing their game.
More, On Glide
The Glide of a disc relies upon the disc being thrown flat relative to the airflow. If the trailing edge of the disc is at the same altitude as the leading edge, then a disc can glide a long way.
This is known as “nose angle”, and it is exceptionally important if discs are to fly far. Any amount of nose-up angle results in a lot of drag, which is converted into altitude, and then the disc stalls, and fades hard left, and short.
Getting nose angle perfect is one of the hardest things in disc golf, and at the top end of the sport, is a major factor in disc performance. Grip is the deciding factor in the nose angle the disc will fly on, and pushing the thumb down firmly on the disc, and pushing the hand down along with it controls the nose angle at release.
The pushing down of the wrist is called Ulnar deviation and is the same movement as shaking hands, you deflect your hand downwards as far as it will go, in order for your friend’s hand to engage with it properly.
Once correct nose angle is applied to a disc throw, the disc will fly its “native” gliding distance. Discs with extremely high Glide ratings may often surprise the thrower, by flying far further than they had expected.
More, On Turn!
All discs will turn (flip) if they have enough airspeed. Airspeed is the speed you throw the disc at, plus or minus any wind speed. Let’s take a look at airspeed and wind speed to see what a dramatic difference it can make to a throw.
Let’s imagine two scenarios on the same teepad. The first is a 20km/h tailwind, and the second is a 20km/h headwind. Let’s take a stable disc, and throw it at 60km/h from the teepad.
In Scenario 1, the airspeed of the disc will be just 40km/h. Whereas…
In Scenario 2, the airspeed is 80km/h!
In the first instance, the disc is going to drop very rapidly because it is flying slowly, and it is going to land well short compared to the no-wind shot. In the second, the disc is going to turn over, because the airspeed the disc feels is that of being thrown 20km/h faster in no wind.
And this is exactly why it is OK for a player to carry a disc which is “too fast” for their arm. Throwing such a disc into a headwind allows it to fly at (or closer to) the proper target airspeed of a disc, and thus it will fly “correctly”, without turning over, and going right.
It is still not OK for a noob to carry a Speed-14 disc. A Speed-7 is just fine!
Discs can do one of three things if they begin turning.
1) Continue to turn. These throws often turn into rollers, and you might get a cut roll (Rolling to the left for an RHBH throw) if it lands at a shallow angle, or a full roller which stands up, and rolls long, depending on the angle of the disc and how stable the disc is. Discs landing below a certain angle of anhyzer will slide rather than roll.
How to roll discs is best explained in this excellent video by Best Disc Golf Discs
2) Turn and then hold. These throws will tend to continue reaching to the right for their entire flight, and then slide rather than cut rolling – the holy grail of throws for an RHBH-only player.
3) Turn a little, hold the turn, and then fade to finish. These are the longest types of golf throw you will generally see on a course. The Hyzer-to-anhyzer-to-fade throw is, however, the least accurate shot choice, so have a wide-open fairway available for one.
More, on Fade
The harder a disc fades, the further off the thrown line the disc deviates – such that a disc with fade 4 or 5 may even finish by skipping sideways relative to the teepad, with no forward motion relative to the target, and plenty of motion lateral to it.
Discs with a lot of fade can move very far from right to left, even after they touch down and skip – especially if there is a right-to-left wind blowing. So they must be thrown very far to the right of the target landing area.
The less a disc fades, the more forwards any skip will be, relative to the target. But discs do need to land on some sort of hyzer angle in order to skip. Discs which land flat will simply slide to a stop.
So a good amount of thought needs to be put into planning a shot so that proper account is taken for the disc fading, and also to allow for any skip distance the landing angle is likely to produce on the surface it hits.
Generally, high fade (overstable) discs are going to be slightly easier to range, albeit with a large lateral component to the landing zone.
More On The Three Disc Types
Stable Discs
These are discs which will fly straight under the power phase of their flight, and will usually fade fairly gently at the end of their flight. Stable fairway drivers will have a tendency to finish with a fairly forward skipping angle.
There are far more stable midrange and putter discs than there are fairway drivers, as higher speed discs tend to fade harder at the end of their flight.
Stable discs will always have “Zero Turn” as part of their flight rating. They’ll have Fade of 0, 1 or even possibly 2.
Overstable discs
These are discs which are designed to go left. They will only fly straight if they are thrown flat with considerable power, and they will always finish strongly left at the end. Overstable drivers may skip long distances left of the intended landing zone.
Overstable discs are required when throwing into a headwind, as they resist the inevitable Turn the extra airspeed of a headwind brings.
Overstable discs are easily identified as they have high Parting Lines. (Right)
Placing an understable driver against an overstable driver on a flat surface will normally see the leading edge of the understable disc slide underneath the leading edge of the overstable disc.
Overstable discs will have either 0 Turn (normally stable), or +1 Turn, which indicates extreme overstability, and a high airspeed requirement.
Overstable discs will always have high Fade numbers; 3, 4, and even 5 Fade. There are no overstable discs which finish straight.
Understable discs
These discs are designed to reach right when thrown flat, or with hyzer, depending on just how understable they are. Many understable discs will not fade at the end of their flight, and will often fly to the right all the way to the ground. Depending on the angle they land they will often roll when they hit the ground. Discs that land above ~45 degrees can stand up and roll long. Discs that land below ~45 degrees will cut-roll to the left.
Understable discs are often designed so that at lower airspeeds they are able to fly very straight – but headwinds will affect their flight shape drastically.
The Parting Lines of understable discs are usually low, and in the case of drivers, always.
Understable discs which are thrown so that they begin reaching to the right are less accurate than flight shapes which do not reach right.
Understable discs will always have negative Turn numbers; -1, -2, -3, -4 and even -5, indicating extremely understable flight, and a high propensity to roll.
Disc Stability is relative to Airspeed
The very great difficulty for new players is that what is understable for one player will not necessarily be understable for another. This is entirely due to the inability of new players to accelerate a disc to the correct flying speed, or failures in form which cause the disc to fly nose up, which will always result in short throws which finish hard left.
How fast a disc is flying through the air dictates how stable it is, and even the most overstable drivers in the world will turn over with enough airspeed. In the reverse situation, some extremely understable drivers like the Mamba, and the Bolt will behave like overstable discs when in the hands of a very low power thrower.
It is therefore tempting, for a beginner to seek a very understable distance driver in order to extend their throwing distance. But this is a poor idea, as controlling high-speed driver nose and hyzer angles are beyond the skill of a beginner. They are far better served throwing understable midrange discs until they gain good control with them, and good distance.
Disc stability is also closely related to spin speed. More is always better.
Just as forward velocity will change a disc's stability, so too does the rate at which it spins. Most new players do not apply enough spin or airspeed to a disc, and additionally, they usually throw with the nose up, further degrading flight performance.
With a good grip, a natural amount of spin is automatically created in the backhand power throw, but the forehand has no mechanism to retain the disc in the hand, and so the timing of the wrist smash in a forehand shot is critical to apply decent spin.
Even extremely good forehand throwers can not match the spin rate of the top backhand throwers - and this is why the world distance record will always be set with a backhand throw.
Less spin equals an earlier fade, and less resistance to the influence of wind and turbulence. More spin means longer flights which hold their hyzer angle with more accuracy and for an extended period of time.
The exact ratio, is that for an optimal spin rate on a throw, half that spin rate will result in twice as much Turn (or "High Speed Turn" as it is sometimes known) while twice as much spin will produce half as much Turn.
Now, it is unlikely a player can double the optimal/average spin rate of a power throw, but it is certainly possible for beginners to throw at half the spin speed.
Disc stability is also affected by weight
The heavier a disc is, the more stable it will tend to be. This is because a lighter disc is accelerated more than a heavy one when the same force is applied to it. Thus, lightweight discs leave your hand at a higher airspeed, and as we now know, higher airspeed makes discs fly a more understable flight path.
So, in general, players will find lightweight discs will fly further than heavier ones, but they will also fly a more understable flight path - turning to the right more.
Lightweight discs are not ideal to throw into a headwind, as the reduced mass means a disc is more heavily affected by wind and turbulence. The extra spinning speed and airspeed does not counteract this. Lightweight discs thrown into headwinds will often turn until they hit the ground and roll.
Only strong and fit Mens Open division players should be using all "Max Weight" discs. It makes much less energy to accelerate a lightweight disc to its flying speed, and thus, women, children and Grand Masters and beyond all benefit from using lighter discs.
Some extreme high-speed driver discs are available in weights as low as ~135 grams, but it is not necessary to go that light. "150 class" discs are perfect for the ladies, and all but the smallest children.
As a Grand Masters age player, my target weight for drivers is now around 172 grams. I still throw max weight midranges and putters, for the stability they offer. I carry three lightweight drivers; a 155 gram VIP Air King (from Feldberg), a 155 gram Star Wraith (From Des Reading), and a 165 gram First Run Champion Mamba (from Disc Golf Hall of Famer buddy, Bob Gentil). Plus a 153 gram Opto Ruby, for very long-range downwind putts.
Basic Flight Shapes
Classic S-shape: a disc which is thrown on a hyzer angle begins to fly to the left, and then flips up to flat (thus flying straight momentarily) and then it turns beyond flat, into anhyzer, and the disc will move to the right for a gliding phase, before finally fading left .
These shots are difficult to throw because wind speed and direction, nose angle, hyzer angle, and altitude are all extremely important. They are also the most inaccurate throws, as when a disc “turns over” the size of the potential landing area increases dramatically.
Flip-to-Flat-and-Fade: Is a very common shot. A disc is propelled out on a slight hyzer angle, and the airspeed flips the disc up to flat, or close to it, followed by a long cruising phase of pure straight flight (or very gentle hyzer flight), and finally fading to finish long.
Flat-to-Anhyzer: An understable disc is thrown on a flat line, and it begins to turn to the right after travelling some distance from the tee. How fast the disc is thrown, and how understable it is will decide how far right the disc will reach, and what angle it will strike the ground.
Pure Anhyzer: The disc is released with an anhyzer angle, and begins turning right the instant the disc leaves the hand. Pure anhyzer shots can be thrown with any disc that will not fade out of the turn before landing. Ideally, a disc will flatten somewhat as it flies so that it will slide and not roll when it touches down.
Anhyzer-to-Hyzer: This is a shot best thrown by experts, as they are difficult to control at anything more than short approach speed.
Typically, a very overstable disc is selected, and thrown on a strong anhyzer angle, at a slightly lower than normal flying speed, to ensure that the overstability of the disc will bring it all the way from its anhyzer line, over to a hyzer angle, to achieve the desired “reverse S’ flight shape.
It is also the mark of a new player who has adopted driver discs before learning how to throw properly.
Pure Hyzer (it’s almost always best!)
In terms of accuracy, there is no doubt the most accurate shot is always a pure hyzer, where a stable or overstable disc is thrown on a steep(ish) hyzer angle, and it maintains that hyzer angle throughout its flight, and carves a single perfect curve through the air.
Professional disc golfers will always choose a pure hyzer if they have the power to reach their landing zone with one.
A very high hyzer throw is called a “spike hyzer” as it lands so steeply that it can’t skip anywhere, but they will sometimes bounce a metre or two from their landing spot. The disc may bend obscenely when it hits hard ground, or create what’s called a “tombstone” by sticking into the ground almost vertically.
Typically, hyzer shots with overstable driver discs will result in some form of skip at the end, the distance of which is dictated by the condition of the landing surface, and the angle and speed of the impact. I call long grass “Velcro”, is it will grab a disc instantly, and prevent skipping. Hard ground may produce skips even longer than the first portion of the flight!
Midranges and putters have far less propensity to skip far, as they create more drag on the ground, and in the air, and they are not landing with nearly as much airspeed as a driver disc.
– Chris/Dingo/Mobius
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