Warning: long reply
Ok I like this idea over all. This could be the beginning of something. This is exactly why the ADI was set up; for someone else to come along and plug these numbers into an actual ranking system where the ranks aren’t just random guesses of skill levels.
So the distance, while it would limit some people like city dwellers, I can see why it might be necessary. Spin drift is a good indicator of an imperfect throw. I know this because I’ve dealt with spin drift issues personally and after fixing it there is a huge difference in accuracy at distance and retention of speed down range. No master can have poor spin and be at that rank. It wouldnt make sense. A master has to typify perfect slinging. Yet spin drift only really plays a major role at approx. 25-40 meters (depending on the size and density of the ammo and the amount of spin and angle of attack) So long range shots play a bigger role here than simply making things difficult for difficulties sake.
10 ranks is perfect in my estimation. As with belt systems in martial arts it gives a quick feeling of accomplishment early on that slows with each additional rank. A graduated system of difficulty.
One issue I think we need to look at and this is open to everyone, please feel free to give your input, is this: ADI struggles to retain relevance with massive increases in distance. So ADI 100 at 100 meters is not just twice as hard as ADI 100 at 50 meters. Multiple different cross winds, aiming so high off the target that you have nothing but blue sky to reference, the increased power needed all increase the difficulty above what the number would suggest. So should we adjust the target size to reflect this? It will still be ridiculously difficult but it will stay in line with the intended effect of an increase of 10 adi per level. If no is the consensus that’s fine. But this is something that needs to be mentioned I feel.
And lastly should we consider reevaluating the top skill levels? Jaegoor right now is a former World Champ and his score here is ADI 14.2 with 17 hits out of 20 throws at 20 ms on a 4ft/120 cm square.
I would hate to have the top levels be so high that they essentially become a joke. I think as slingers we will see big increases in max skill levels in the coming decades as people begin to find new techniques that greatly increase consistency. We know this looking at pretty much every other sport. But going from 14.2 at 20 meters to 100% accuracy over 10 shots at 100 meters might be too much to ask of anyone.
Ok, long post, but hopefully thought provoking. Please feel free add your own thoughts, constructive criticism, etc. Thanks.