There are four main factors that determine the flight path of a disc golf disc:
- Throw type (right-handed, left-handed; backhand, forehand)
- Disc stability (overstable, understable)
- Release angle (hyzer, flat, anhyzer)
- Environmental variables (wind, altitude, etc.)
This is whether you’re throwing right-handed or left-handed, and backhand or forehand.
The most basic axiom of disc golf physics is that for a right-handed backhand (RHBH) or left-handed forehand (LHFH) throw:
- at sufficiently high speed (the start of the throw) the disc will bank right (turn)
- at sufficiently low speed (the end of the throw) the disc will bank left (fade)
Viewed from above, a typical RHBH/LHFH throw’s flight path will look like this (from Disc Golf Puttheads):
By contrast, left-handed backhand (LHBH) and right-handed forehand (RHFH) throws are exactly the opposite. When they turn, they bank left, and when they fade, they bank right.
Most examples below, unless otherwise noted, are for RHBH.
Discs generally exist on a spectrum from understable to overstable. The disc’s stability can be derived from its flight numbers:
- discs with high turn and low fade are understable
- discs with low turn and high fade are overstable
For example, if you throw an understable disc flat RHBH, then it will turn (bank right) pretty sharply, and then fade (bank left) a little bit at the end. How much the disc will turn or fade depends on its flight numbers.
You can release a disc on a hyzer angle, flat, or on an anhyzer angle.
|From behind, the disc looks like this when thrown RHBH||/||—||\|
|Definition||disc’s outside edge is lower than inside edge||disc’s outside edge is level with inside edge||disc’s outside edge is higher than inside edge|
Let’s consider the same understable disc example above. Now imagine if instead of releasing it flat RHBH, you release it on a RHBH hyzer, that is to say, already banked left.
Now when the disc turns and banks right from its understability, it will “flip up” flat instead and fly straight. And since understable discs don’t fade very much, the flight will stay flat and straight for a long time, even as it slows and lands.
This is one of the most important throws in disc golf, called a “hyzerflip”, and is particularly useful for throwing long and straight. But it is only one of 6 total combinations of release angle and stability. The below table describes each possible shot shape, assuming a RHBH/LHFH throw:
|Overstable disc||The disc will immediately fade hard left. If thrown high into the air this is known as a “spike hyzer”.||The disc will fade left. The most standard, natural shot in disc golf.||Flex shot: the disc will flex right before flattening and fading back left.|
|Understable disc||Hyzerflip: the disc will “flip up” to flat, then fade left a little bit.||The disc will “turn over” gradually right, and may fade back to straight (called an S-shot) or simply keep falling on that angle (called a “turnover”).||The disc will immediately turn hard right. This is the easiest way to throw a RHBH roller, if desired.|
Environmental variables can be thought of as altering the flight characteristics of your disc, as follows:
|Throwing …||…will make a disc more …||To compensate, throw a disc that is more …|
|into a headwind||understable||overstable|
|with a tailwind||overstable||understable|
|down a hill||understable||overstable|
|up a hill||overstable||understable|
|at lower altitude||understable||overstable|
|at higher altitude||overstable||understable|
|in cold thin air||understable||overstable|
|in thick humid air||overstable||understable|
|a lighter disc||understable||N/A|
|a heavier disc||overstable||N/A|
|an older disc||understable||N/A|
|a newer disc||overstable||N/A|
Take wind as an example. Normally, your disc’s airspeed is similar to your groundspeed. But if you throw into a headwind, your disc’s airspeed is much faster than usual (the air is hitting the front of the disc a lot faster). As such, it’s as if you threw the disc much faster, which makes your disc more understable. So if you decide you want to compensate for the headwind, you might throw a more overstable disc.
Armed with this information, you can make educated decisions about what disc to throw and how to throw it.
For example, if you’re righthanded and face a dogleg right hole, you have a few options:
- You can throw an overstable disc flat RHFH
- You can throw an understable disc flat RHBH
- You can throw an overstable disc on an anhyzer RHBH, if you want the disc to flex back left at the end
- You can throw an understable disc on a hyzer RHFH, if you want a long straight flight at first before fading right only very gently
Then you notice there’s a strong headwind. So you compensate: for your RHFH, instead of throwing the overstable disc flat, you put it on a slight hyzer, or throw an even more overstable disc. Alternatively, if you don’t have a good forehand, and were planning to throw an understable disc flat RHBH, you might now throw a neutral stability disc RHBH flat instead and still get it to turn over and bank right.
These are the core basics of flight paths. There are a few other advanced factors not discussed here:
- how crosswinds affect discs (exposing the bottom of the disc to the wind is generally ill-advised)
- how the landing angle affects the disc’s “skip” on the ground
- how to select discs to reduce variance (for example, if you accidentally overpower a very overstable disc, it will still reliably fade and land in about the same spot, which is one reason why very overstable approach discs are so popular)
- how utility shots, like scoobers, tomahawks, and thumbers fly