Terminology Clarification

[Blobfish]

Hey DGCR family,
I think many users confuse the concept of stability versus neutrality and I'm one of them and I'm trying to clarify a few things.

Here is how I interpret the terms:

Neutral is how close to "ending where you aim" your disc will fly when thrown properly. It can fly straight and end straight like an Innova Mako3 or it can do a big S like an Innova Cobra, but it ends up in line with your aim. Back when Infinitediscs had a live chat, one of their helpers once told me that you can add the turn numbers and fade numbers and a negative number means it ends to your right (for RHBH), 0 means it ends straight, and a positive number means it ends to the left (for RHBH). So I interpret Turn+Fade=0 to be neutral. Is this a valid interpretation?

Okay, on to stability. A stable disc is one that holds the line you put it on because it fights both the natural inclination to turn over with a high rotational speed (and this gives it "HSS" or High Speed Stability) as well as the disc's natural inclination to precess (fade) as it slows (which gives it "LSS" or Low Speed Stability). Thus a "stable" disc should have both a low turn number, which should determine how much angular speed will cause the disc to deviate from neutral to the right and a low fade number which should determine how much the disc will deviate to the left as the angular speed approaches zero. But by going with this definition alone, only discs like the 0/0 mako should truly be "stable" and that's not the case, and hence my confusion with the term.

So to further muddy the language, Overstability and Understability are used.

As far as I understand, Overstable means a disc that really fights the turn (very high speed stable and thus a low turn number) but generally has a low value for low speed stability which is why it fades pretty hard and has a high fade number. This is why the faster airspeeds associated with either strong throws and/or headwinds allow for overstable discs to fly straight instead of turning over and they have a predictable fading finish.

Conversely, Understable enables slower angular speeds to turn the disc and thus have low high speed stability meaning a high turn number. I'm not really sure why high speed instability geometry would result in greater low speed stability, but generally, understable discs tend to have lower fade numbers which implies a greater amount of LSS or am I mistaken?

So finally, when we say "This disc is stable", are we talking about HSS? LSS? Both?

For example from Infinite Discs' website

Innova Cobra: 4/5/-2/2 rated: "stable"
Discraft Buzzz: 5/4/-1/1 rated: "stable"
Innova Shark: 4/4/0/2 rated: "overstable"
Daredevil Moose: 4/5/0/2 rated: "stable"
Discraft Rattler: 2/3/-1/1 rated: "overstable"
Discraft XL: 8/5/-1/2: rated "stable"


I like the buzzz because in my mind it is very stable. It holds straight, hyzer, and anhyzer lines very well. To me, that is stable. On the other hand, the cobra turns over immediately for me and though it does try to fade back, I would never call the cobra "stable", even if it might be "neutral".

So yeah, if you got this far, please chime in on what I must be misinterpreting. Thank you!

 

[wolfmandragon]

Stable : holds the line when thrown clean.
Overstable: holds the line when thrown dirty or overspeed.
Understable: does not hold the line when thrown clean.

Fade does not directly apply to stability as there are understable disc with very strong fade..

The more angular velocity a disc has, the more stable it flies. Lids demonstrate this wonderfully.

A neutral disc is one where both the turn and the fade is 0, or very close
And
Neither has strong turn nor fade.
A S turn disc is not neutral even if the hss - lss is 0.
The Comet is a perfect example of a neutral disc.

 

[wolfmandragon]

Edit window expired:

Technically it is angular momentum, not angular velocity, that adds stability. More angular velocity (spin) does give more angular momentum but so does having more weight forwards the edge of the disc (MVP overmolds and single shot lids are good examples)

 

[dreadlock86]

Neutral is how close to "ending where you aim" your disc will fly when thrown properly.
Is this a valid interpretation?

no

neutral means flies straight. it is not turn+fade=0
neutral means what you think stable means

Okay, on to stability.

So finally, when we say "This disc is stable", are we talking about HSS? LSS? Both?

a lot of people are wrong on this. it's a common misunderstanding that overstable means turning left, stable means straight, and understable means turning right.

think of stability as a spectrum not 3 separate categories:

more stable <--------------------> less stable

if you wanted to put them in 3 categories, they would be overstable, neutral, understable

of course you have to clarify what people mean when they describe a disc because there is so much misunderstanding of these terms, even among very experienced players or pros. but properly understood, when someone says a disc is stable it means it is in the range of somewhat to very overstable. said another way, a stable disc is one where turn+fade= a positive number

 

[ru4por]

I don't really use the terms neutral or neutrality. Stability is certainly a sliding scale. I don't see the sense in making discussions with my disc golf buddies overly complicated. Assuming you release a disc flat, at the same speed RHBH....overstable discs want to go left, stable discs want to go straight and understable discs want to go right. There are other factors that can be added to the equation. They are just labels for what happens, in the individual flight of your own discs. Each disc flies differently for every unique player. Given the different flight characteristics of different plastics within a mold, talking about stability is a moving target at best, unquantifiable at worst. I see it a more of a vague concept that a definable term or discussion point.

 

[ejvogie]

no

neutral means flies straight. it is not turn+fade=0
neutral means what you think stable means



a lot of people are wrong on this. it's a common misunderstanding that overstable means turning left, stable means straight, and understable means turning right.

think of stability as a spectrum not 3 separate categories:

more OVERstable <--------------------> MORE UNDERstable

if you wanted to put them in 3 categories, they would be overstable, neutral, understable

of course you have to clarify what people mean when they describe a disc because there is so much misunderstanding of these terms, even among very experienced players or pros. but properly understood, when someone says a disc is stable it means it is in the range of somewhat to very overstable. said another way, a stable disc is one where turn+fade= a positive number

FTFY

 

[7ontheline]

Hey DGCR family,Hello friends 7 here
I think many users confuse the concept of stability versus neutrality and I'm one of them and I'm trying to clarify a few things.

Here is how I interpret the terms:

Neutral is how close to "ending where you aim" your disc will fly when thrown properly. It can fly straight and end straight like an Innova Mako3 or it can do a big S like an Innova Cobra, but it ends up in line with your aim. Back when Infinitediscs had a live chat, one of their helpers once told me that you can add the turn numbers and fade numbers and a negative number means it ends to your right (for RHBH), 0 means it ends straight, and a positive number means it ends to the left (for RHBH). So I interpret Turn+Fade=0 to be neutral. Is this a valid interpretation?
A complete noob that's never thrown a Mako3 or any other disc will need a beat to dog chew toy DX Cobra if they want their 200' max Distance drive to be "neutral" for them. I accept your definition of Neutral if you want to say that's how it flies for you to get a point where you were "ending where you aim", but I could throw a 300'+ Firebird directly into a strong headwind to end directly in front of me but I'd never agree that a Firebird should be considered "neutral".

Neutral, too me, means that the disc tends to fly straight at normal for me 80-85% power, turn = 0 and fade = 0. For me, that means my First Run beat Z Buzzz goes completely straight at 300' with no wind on a less than 10' line. If I throw it with more power to hit 340' on a similar 10' high line, it'll start to turn/show -1.5HSS/ and not fade/ -1 LSS. The Teebird, is beloved for it's neutral flight, However, a Teebird isn't the true thing of beauty that it'll become until they lose their Fade/LSS and get straighter and straighter as they age somehow retaining their resistance to turn/HSS. Is a Teebird Neutral? Depends who's throwing it, what the conditions are, what plastic it's molded in, and condition of said plastic.



Okay, on to stability. A stable disc is one that holds the line you put it on because it fights both the natural inclination to turn over with a high rotational speed (and this gives it "HSS" or High Speed Stability) as well as the disc's natural inclination to precess (fade) as it slows (which gives it "LSS" or Low Speed Stability). Thus a "stable" disc should have both a low turn number, which should determine how much angular speed will cause the disc to deviate from neutral to the right and a low fade number which should determine how much the disc will deviate to the left as the angular speed approaches zero. But by going with this definition alone, only discs like the 0/0 mako should truly be "stable" and that's not the case, and hence my confusion with the term.Depends who's throwing it, what the conditions are, and what plastic it's molded in, and condition of said plastic. I'd consider my well seasoned 11x Teebird to be a stable flier. After years of work I'd give my subjective flight numbers of 7/5/-.5/.5 It's not exactly 0/0 and started out 0/2. Currently, at 350' on a less than 10' high line with no wind it will hold a line to the ground with less than 10' lateral moverment. My buddy who throws Destroyers 500' would call it "understable" as it would turnover and cut roll if he really got on it. A noob that can't throw anything 300' might find it "overstable" as it will most likely finish well to the left.

Just keep in mind that flight numbers are just guidelines that vary greatly between different plastic types (Champion/Lucid/Evo/Pinnacle/Proton etc. and because the plastic pellets are constantly changing different runs within a particular manufacturer will differ. Also, the flight numbers assigned by competing manufacturers have their own totally subjective ratings.

So to further muddy the language, Overstability and Understability are used.

As far as I understand, Overstable means a disc that really fights the turn (very high speed stable and thus a low turn number) but generally has a lowhigh value for low speed stability which is why it fades pretty hard and has a high fade number. This is why the faster airspeeds associated with either strong throws and/or headwinds allow for overstable discs to fly straight instead of turning over and they have a predictable fading finish.

Conversely, Understable enables slower angular speeds to turn the disc and thus have low high speed stability meaning a high low/negative turn number. I'm not really sure why high speed instability geometry would result in greater low speed stability(Understable discs usually have less HSS and less LSS flight#s), but generally, understable discs tend to have lower fade numbers which implies a greaterlesser amount of LSS or am I mistaken?
For example; Teebird#s 7/5/0/2 vs Leopard 6/5/-2/1 turn/HSS is less as is fade/LSS
So finally, when we say "This disc is stable", are we talking about HSS? LSS? Both?

For me both but you gotta be clear here. There's a lot of confusion and room for interpretation. I usually say stable straight if I want to describe a shot that follows a point and shoot bee line on a flat release for a stated distance. I can also hyzer flip an understable disc to straight or flex an overstable disc for straight, depends on the best available line. **Most folks I play with call "stable" to mean the disc with fly at least partly overstable or not broken in.**

For example from Infinite Discs' website

Innova Cobra: 4/5/-2/2 rated: "stable"
Discraft Buzzz: 5/4/-1/1 rated: "stable"
Innova Shark: 4/4/0/2 rated: "overstable"
Daredevil Moose: 4/5/0/2 rated: "stable"
Discraft Rattler: 2/3/-1/1 rated: "overstable"
Discraft XL: 8/5/-1/2: rated "stable"

Good for Infinite for making it easy. Again, flight numbers between manufactures is damn near unless when assessing how it'll compare to a different manufacturer. Also, I hate to break it to you but no two discs will ever fly exactly the same.


I like the buzzz because in my mind it is very stable. It holds straight, hyzer, and anhyzer lines very well. To me, that is stable. On the other hand, the cobra turns over immediately for me and though it does try to fade back, I would never call the cobra "stable", even if it might be "neutral". cobras are understable my noob friend, they need hyzer to fly a straight line. If you max your cobra at 225', I'm gonna bet it doesn't have any turn/HSS=0 or fade/LSS=0 and therefore "Neutral" for you.

So yeah, if you got this far, please chime in on what I must be misinterpreting. Thank you!

Have a great day




$5 says Streets will swoop in here with some whitty one liner and get more likes than me

 

[7ontheline]

if you wanted to put them in 3 categories, they would be overstable, stable, understable

FTFY

 

[Hampstead]

Just adding an aside to general terminology.

OOP means Out Of Production, not an Oops aka X-Out, like I have heard some folks reference.

 

[GripEnemy]

$5 says Streets will swoop in here with some whitty one liner and get more likes than me

Reaction gifs are a balancing act.

Streets' drives however, are not:

 

[Doofenshmirtz]

Okay, on to stability. A stable disc is one that holds the line you put it on because it fights both the natural inclination to turn over with a high rotational speed (and this gives it "HSS" or High Speed Stability) as well as the disc's natural inclination to precess (fade) as it slows (which gives it "LSS" or Low Speed Stability).

Precession causes both turnover and fade. I'm not sure I understand what you mean by "natural inclination."

 

[dreadlock86]

a lot of people are wrong on this.

FTFY

FTFY

to the OP, see what i mean?
maybe it's more like most people

 

[DiscFifty]

it's a common misunderstanding that overstable means turning left, stable means straight, and understable means turning right.

I don't know, it's always been pretty black and white to me, even from the start when I took my first lesson years ago. I was told stable=straight, (rhbh) overstable=left, understable=right. It was also completely obvious throwing the disc softer increased overstability while throwing the disc harder increased understability. Never had anyone describe a disc's flight as "neutral". Maybe different terminology has evolved over the years in different markets.

 

[dreadlock86]

what seems black and white to me is that the term stable is meaningless if stability is a factor in the mechanics of a flying disc. if it's a factor, you either have more of it or less of it and therefore it is a continuum not a series of categories. one should be able to say "this disc has a less stable flight than that one" or "premium plastic is generally more stable than base plastic".

i realize that many just say "more overstable" or "more understable" instead and think stable means neutral and that might even be the majority of disc golfers but it sounds redundant and stupid to me. neutral is also a far more obvious and intuitive description than stable to describe a straight flight. and it also doesn't make sense to say that one neutral disc is "more overstable" or "more understable" than another when both discs are neither of those things.

 

[BogeyNoMore]

I think anyone reading this thread will be glad if they click this link. Best explanation of stability and how it relates to disc flight I've seen for the non-physicist.

In short: Spin is what gives a disc stability. Without spin, a disc launched at a given velocity won't achieve anything resembling flight. Doesn't matter if it's a Drone or a Stratus... launch a disc with zero spin and it basically becomes a not so aerodynamic projectile, and will flounder like a wounded duck.

"Stability" is a relative term, used to describe how much spin a given disc needs to achieve a stable flight at a given velocity. By stable flight, I mean the disc holds the line it's thrown on (at least until the speed slows to where fade takes over the flight). When thrown flat, a stable flight is straight. When thrown on a hyzer, a stable flight will go to the left (RHBH). Thrown on an anhyzer, a stable flight will go to the right (RHBH).

All other things being equal (and realistically, they seldom are):
Understable disc: requires more spin hold its line.
Overstable disc: requires less spin to hold its line.
Stable disc: falls somewhere between these two.

If a player gets a disc to turn at a certain velocity, it's understable at that combination of speed and spin.
If that player is able to increase spin, without changing speed, that same disc will achieve a straighter flight.

The rub is that we're all a bit different, and throw with differing amounts (or more correctly, ratios) of spin vs. speed.
Hence what seems stable to one person, may behave overstable (or understable) to other players.

 

[ru4por]

I think anyone reading this thread will be glad if they click this link. Best explanation of stability and how it relates to disc flight I've seen for the non-physicist.

In short: Spin is what gives a disc stability. Without spin, a disc launched at a given velocity won't achieve anything resembling flight. Doesn't matter if it's a Drone or a Stratus... launch a disc with zero spin and it basically becomes a not so aerodynamic projectile, and will flounder like a wounded duck.

"Stability" is a relative term, used to describe how much spin a given disc needs to achieve a stable flight at a given velocity. By stable flight, I mean the disc holds the line it's thrown on (at least until the speed slows to where fade takes over the flight). When thrown flat, a stable flight is straight. When thrown on a hyzer, a stable flight will go to the left (RHBH). Thrown on an anhyzer, a stable flight will go to the right (RHBH).

All other things being equal (and realistically, they seldom are):
Understable disc: requires more spin hold its line.
Overstable disc: requires less spin to hold its line.
Stable disc: falls somewhere between these two.

If a player gets a disc to turn at a certain velocity, it's understable at that combination of speed and spin.
If that player is able to increase spin, without changing speed, that same disc will achieve a straighter flight.

The rub is that we're all a bit different, and throw with differing amounts (or more correctly, ratios) of spin vs. speed.
Hence what seems stable to one person, may behave overstable (or understable) to other players.

Good post.

And I might add, discs are all a little bit different. Same mold, same weight, same plastice....variances exist.

 

[cheesethin]

I think anyone reading this thread will be glad if they click this link. Best explanation of stability and how it relates to disc flight I've seen for the non-physicist.

That link gets the cause of turn and fade wrong. It repeats the old 'air moves faster over one side of the disc than the other' fallacy. The centre of lift being in-front or behind the centre of gravity of the disc essentially tries to push the nose up or down, and this force gets translated via gyroscopic precession into fade or turn.

 

[BogeyNoMore]

That link gets the cause of turn and fade wrong. It repeats the old 'air moves faster over one side of the disc than the other' fallacy. The centre of lift being in-front or behind the centre of gravity of the disc essentially tries to push the nose up or down, and this force gets translated via gyroscopic precession into fade or turn.

Understood. I referenced stability, and the part about understable requiring more spin, and overstable requiring less.

 

[Jay Dub]

to the OP, see what i mean?
maybe it's more like most people

You're all wrong.

Definition of stable

(Entry 1 of 3)
1 : a building in which domestic animals are sheltered and fed especially : such a building having stalls or compartments

 

[cheesethin]

Understood. I referenced stability, and the part about understable requiring more spin, and overstable requiring less.

Also understood

I just couldn't let the (incidental to your point) falsehood go without throwing a spear into it's heart.