Disc Golf Numbers Explained – In Depth





Disc Golf Numbers Explained – Speed, Glide, Turn, Fade Overstable, Understable !!What does it all mean, and how do you apply it to buying the right disc for you? There are a couple of ways this usually plays out. You likely either picked the one with the coolest name, or the fastest speed rating. Time to bang some chains! So you get out to the course with your new disc just knowing an ace is in your near future. Somehow your new disc worse than the one you found in the creek with gouges all along the rim. Chances are that it’s not your discs fault. It could just be that you weren’t meant for one another. So lets dive right in, and get to the bottom of this once and for all.

There are a few terms you should be familiar with before dive into the numbers.

Everything below is related to clockwise rotating discs. Reverse for counter-clockwiseoverstable understable stable

overstable- will go left during the high speed portion of flight.

stable- will go straight during the high speed portion of flight.

understable- will go right during the high speed portion of flight.

There are a few different rating systems used by disc manufacturers. Vibram, Discraft, and Innova all use a different system.

Disc Golf Numbers Explained – The SDLC or Secret Disc Launch Code – Four number System

It is an ancient myth that once a man deciphered the SDLC and launched a disc into orbit.

Speed – the minimum speed required for proper flight.

If you’re not first you’re last! More speed = more distance right? Well this is a very misleading rating so lets think of it as more of a required skill level than disc speed. They are classified in a few categories. Putters – range from 1 to 3 speed. Midrange- range from 4-5 speed. Fairway drivers- range from 6-8 speed. Distance drivers- range from 9-14 speed.

How speed  relates to disc selection.

When I started playing disc golf I could barely eclipse the 225 Ft mark. So I started shopping online to find a distance driver that would get me over the hump. I looked through flight charts trying to find the straightest and longest pattern. “This one says it goes 300 plus Ft, and barely curves left at the end.” I thought this must be the one for me. When I got to the course and saw it in live action it was nothing like advertised. Well the problem wasn’t in the disc at all. I was throwing a 13 speed disc with a 10 speed arm.

The speed rating  isn’t how fast the disc travels. Although a 13 speed is more aerodynamic than a 10 speed driver. That just means the potential is there for more speed. Your arm is where that speed has to come from. So if your arm can only get a disc up to a “10” at full power then every disc rated higher will be overstable, and will go hard left far shorter than it’s designed flight pattern.  This can be used to your advantage if you have an obstacle you need to go around or maybe a hazard you want to be sure to stay left of. If you throw a disc rated at “9” with “14” power then it will Turn hard right sailing way off course, and possibly crashing straight into the ground.

Glide – the degree to which a disc stays aloft.

Rated from 1-7

How glide  relates to disc selection.

So basically a high glide disc has the potential to stay in the air longer than one with low glide. However this comes with a lot of variables. Wind conditions probably have the biggest effect on glide. The faster you throw a disc the more lift ( glide ) it will have. The slower you throw it the less lift it will have. So if you are throwing into a 15 MPH wind it’s like you are throwing 15 Mph faster and the disc will have more lift. In this case you would want to use a disc with a lower glide rating in order to make it more accurate. The opposite is true for throwing with the wind.

When you are a beginner you want a disc with a higher glide. This will allow you to get a little extra distance on your throw. Weight can also affect the lift of your disc. Lighter discs have a potential for more lift, while heavier ones have less.

Turn – the degree that a disc goes right during the high speed portion of flight .

Ranges from +1 to -5. ( +1 = overstable, 0 = stable,-1 to -5 = understable )

How Turn  relates to disc selection

The speed that you throw your disc has a huge factor on Turn. So even if you have an understable disc , and you don’t get it up to speed it will still go left much sooner than it was intended. If you throw a stable to overstable disc it can still go right if thrown much faster than the speed rating.

A +1 ( overstable disc ) is harder to get distance out of because it will almost immediately curve to the left which means it will hit the ground sooner. This can also be more accurate since you don’t have much chance of it sailing to the right. Understable = more accurate into the wind.

A 0 turn rating ( stable ) means that it will stay straight until it slows. Then it will fade to the left.

A -1 to -5 ( understable ) disc will start right then go left as it slows. Which can give you a little more distance. Can also be less accurate in the wind. Be careful with understable discs though. It’s a helpless feeling to watch your drive start right ….. then just keep going right… and land 200 FT past and to the right of the basket. You can also use this to your advantage once you figure out how to make it keep going right intentionally.

Fade – the degree that a disc goes left during the slow speed portion of flight

Ranges from 0 to 5

How Fade relates to disc selection

If your disc has a 0 Fade then it should stay straight at the end of the throw, and is likely to get more distance. A disc with a  Fade rating of 5 will break hard left at the end of the throw cutting your distance a little shorter. A high fade disc will give you more control into the wind. If you throw an understable disc with high fade it can make an S-shaped flight pattern which can give you even a little more distance.



Disc Golf Numbers Explained – The Vibram System

This system only has 3 numbers. One from 0-30 for the degree Turn at the beginning, one is the ideal speed in MPH the disc should be thrown to get the designed flight pattern, and one from 0-30 for the degree of Fade at the end of flight. Vibram even stamps the flight pattern on the bottom of their discs. That is pretty basic. sometimes simple is good right?

Disc Golf Numbers Explained – The Discraft way

It doesn’t get much simpler than the Discraft ratings. It ranges from a 3, 2, 1, 0, -1, -2, -3,

3 being overstable, and -3 being understable.

If you Don’t like deciphering the Secret Disc Launch Codes this is the way to go. Much less of a headache.

Wrapping up the numbers

Wow! That Four Number System is by far the most complicated rating system in all of the lands. By now you probably think you will need hire a team of engineers and scientists to help you figure out which disc to buy. Well These ratings are to be taken with a grain of salt… whatever that means. Some say that the numbers are meaningless. I feel like they mostly useful as a reference point. For example if you have a disc that you like you can use its flight ratings as a reference point for others that are similar.















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