… Allow me to break the issue down by numbers starting with speed. As I see it (bear in mind I’m not a physicist), disc speed is a product of two things generally: wing profile and, by far most important, the force applied to it I.E. arm-speed. Generally speaking, highest speed discs have the longest wing allowed by the PDGA, and this makes sense. However, a speed 14 disc thrown by the Eagle McMahon is not going to travel at the same speed as the same disc thrown by Joe Recreational or even the local course hero. Most can accept this on its own, but the trickle-down is that speed is the governing factor of the other numbers as well. In other words, a speed 14 disc at 70 mph won’t turn and fade the same as when it’s thrown at 50 mph or anything in between. Therefore, the numbers very depending on who’s throwing the disc.
Then there’s the additional factor of spin. This is where I’ll leave details to an expert, but from what I’ve seen on the course and in the field, which includes Christian Sandstrom bombing DX Valkyries nearly 200 m at the 2003 World Disc Games, spin is key to glide. Much like speed, glide is dependent on disc shape, though less about wing profile as the overall profile and particularly the area under the flight plate. Though even more significant in terms of contributing to glide is the amount of rotation on the disc. I will venture to say that regardless of the glide number assigned to any disc or degree of dome, without sufficient rotation the difference in flight will be negligible. So again, disc glide is dependent on the rate of rotation, which is presumably highest immediately following the point of release and gradually slows to the point where the disc comes to rest.
Of course, there are environmental factors to consider also. It’s not by accident that serious distance contests happen in the desert at high elevation, where atmospheric pressure is relatively low and thermals radiating off hardpan assists to elevate the disc. And then there is the almighty wind to consider. When combined with the right tilt