Introduction The Elo models introduced last time, which were the models used on Predictaball from 2017-2019, worked very well but with some limitations. Firstly, the parameters used in the rating update equation (home advantage and margin of victory multiplier) were chosen manually by inspection for each league. If I wanted to apply Predictaball to a whole new set of leagues (yet alone sports!) I’d need to go through each one to identify new parameters - hardly ideal!