The resistance of a rotating body to a change in its plane of rotation. The faster a body spins (the greater its angular velocity), the greater the stability of the body in its particular position or orientation. Gyroscopic stability accounts for the stability of a spinning discus or a spinning football in American football.
Stable = flat, not going left, not going right. Stop spouting bad information.
/overstable
\understable
_stable.[/]
So by your definition, how many discs are stable?
very very very few. I would consider the comet the closest thing to stable. Once it beats in a little bit I think it will be true stable. It's the closest thing to stable I've ever thrown though. The buzzz is slightly overstable, but it is high speed stable.
It's like the speed limit, you are generally over it or under it. Majority of people aren't going to be going 55.0 mph. They will be going between about 50 mph and 60 mph, not counting speeders. If you are going 53, are you closer to the speed limit than someone going 52? No, it also will be closer than someone going 59. But we don't generally compare something on the opposite side like that. A leopard is more stable than a sidewinder, it's also more stable than an Xcal. But we just don't compare it that way.
Overstable does NOT mean it has "more stability". What makes a disc truly stable is the the range of velocity to spin of the disc where the advance ratio makes the disc stay gyroscopically stable. A destroyer can be thrown and become high speed stable, but once it slows down, the advance ratio changes and the center of lift changes on the disc making it fade. For a disc to be truly stable, it would need to stay stable over such a wide variety of speeds that at full power it was stable, but even as it slowed down (until a certain point, it can't go straight with no spin) it would still stay straight. To me, that's the comet.
That's really why the comet is such a great learning tool. It can be thrown at full power and stay straight the entire time, only at the last bit of it's flight will it fall, it doesn't really fade out, just falls. ANY disc will fade if you put it up in the air long enough, pushing a comet out it will eventually slow down with air friction enough to just not have enough spin anymore. Being stable like the comet allows you to also put it on a line, and it will hold it. It will not flip over more, or come back to pan out.