@ricardoV94 's suggestion is good. You may also like the paper on Glicko: https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=f40f40bc5e4e3935a2203208b1f0408324c7d527
If you’re already familiar with some statistical notation, it shows you how you can set up a Bayesian model similar to Elo; in fact it’s arguably a bit more sophisticated since you can infer players’ skill like Elo but also the uncertainty about that skill.