The rotation of a Frisbee is what keeps the disc centered and stable when thrown. If thrown with no spin, a Frisbee will rapidly destabilize. When rotational motion is added, though, a gyroscope effect happens, keeping the disc in line with its original orientation, similar to bicycle wheels spinning and keeping a bike upright.

The faster the disc is spun, the more rotational momentum will be present in the Frisbee during flight, and the more stable it will be.

In the above figure, the greater rotational velocity (ώ) is, the more stable the disc's flight. A greater radius (r) would also give an increased angular momentum, as well.

One note is that, although small, drag will slow the rotation speed over time. This means that there is a slight angular acceleration (ά) in the direction opposite the rotational motion.