With respect to Shane’s 824 rating from 10 years ago, I think you need to account for the time it took for everyone’s rating to settle. While I’m sure players improved over time, a lot of the rating increase was likely driven by the need to get enough games into the system and enough connections established. At that point, when top players were sitting between 780 and 800, it was difficult for Shane to go much higher than that. Once the professional field became more connected and spread out on the scale, his rating and those of other top players adjusted upward.
In terms of the broader question, I do think you would end up with a similar scale if Fargo had been applied during the 70s and 80s. If you managed to capture a similarly representative player population, the lower and middle portions of the player base would provide a fairly stable anchor. The lowest skill levels are constrained by human ability and the learning curve of the game itself. A player who can barely pocket balls in 1976 looks an awful lot like a player who can barely pocket balls in 2026. From there, you still have players who beat those beginners most of the time, players who beat those players most of the time, and so on. So while the skill level of pros and top amateurs may change, there will always be that player who consistently beats beginners, hovers around the 400 level, and gets pummeled by the more serious players. What changes is the number of strong players above them and how separated those groups become.
One caveat might be the relative newness of 9-ball as the primary competitive game during the 70s compared to now. You could argue that without the benefit of modern breaking techniques, racking knowledge, safety play, kicking systems, and overall strategic knowledge, the scale at the top end might end up being a bit more compressed. On the other hand, during the era of two-foul 9-ball, you may have seen more separation between the top players and the rest of the pack if it meaningfully reduced the influence of luck. Once the game shifted to one-foul ball-in-hand, I suspect the ratings may have compressed somewhat. Ultimately, how much the scale changes probably depends on whether those variables increase or decrease volatility in match outcomes.
