Support chess ranking according to standard ranking rules
ramou opened this issue ยท 1 comments
When playing on a ranked table, only complete games get ranked. I don't want to put in time trying to think about how a player might blow up the table to avoid a losing score. Ranking makes you stronger. If you want to be an ass, people won't play with you... if it gets bad, I'll track incomplete games with the option for both players to agree to annul. Keep classy, you chess-playing minecrafters.
Use the Elo Rating System
It turns out this isn't super clear.
So, if you have players with rating R1 and R2. They play a game and score S1 and S2, where that score is 1 point for a win, 0.5 points for a draw and nothing for a loss. Their new ratings, denoted by R'1 and R'2 would be:
R'1 = R1 + K*(S1-(10R1/T)/(10R1/T+10R2/T))
R'2 = R2 +K*(S2-(10R2/T)/(10R1/T+10R2/T))
K and T would be configurable in the mod and would default to 32 and 400 respectively. If people really wanted it, I'd allow for K to scale with ratings in a way specified in the config, but this seems a reasonable starting point.