Earlier quoted context omitted.
Thanks for the feedback! Always good to hear from chess players with a FIDE rating that it's working :) If anyone wants more info on how this works, check out this post with more details: https://www.chessmonitor.com/blog/2023-elo-calculation
I’d suggest fitting an isotonic regression instead. I think it’s a reasonable expectation that online and FIDE ratings are monotonically related but it seems unlikely to me that they are linearly related even though it may be an ok approximation for players in a particular rating range. I suspect that the online population — especially at lower ratings — is significantly different to the over the board population. I…
Thanks, I'll look into this!