Right, I see what you mean now. That’s an interesting idea. I have plans to improve the ranking system, although unfortunately quite low priority at the moment, and will look into this at the time.
I’m going to look at implementing WHR instead of glicko, and it’s possible that the w parameter of the Weiner process could be set to zero for the puzzle’s ratings only, essentially making this a static rating system from the point of view of the puzzles. However, I have not comprehended the paper enough to determine this yet.
Thanks for looking at the code! I think the BitBoard part of it should be really efficient, but the performance is still way below state-of-the-art. However, there’s loads of stuff I can do in that area, and is one of the highest priorities with that project because otherwise it can’t generate very difficult puzzles.