How Elo ratings work: a maths EPQ idea
A title to start from
How does the Elo rating system work, and is it a fair way to rank teams or players?
Why it works as an EPQ
A logistic formula and an update rule you can implement, test on results and tune.
Scope and difficulty
Solid. Solid. Implement on one season of public results.
The maths
Builds on these A Level topics: Exponentials and logarithms · Probability · Sequences and series.
You would learn:
- Logistic curves
- Update rules and the K-factor
- Testing predictions
One possible plan
- Derive the expected score formula and the update rule.
- Run Elo on a season of results.
- Test its predictions and tune K.
- Judge it against league tables.
Pitfalls
- Tuning on the same data you test on.
- Draws and home advantage ignored.
Where to start reading
- Search for: Elo rating system expected score formula
- Search for: Elo football home advantage
Making something? Read the artefact guide first: an artefact still needs a research-based written report.
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