Algorithms
15 posts
Margin of Victory: Massey and Pythagorean
Two rating systems that read the scoreboard instead of just the result, and three things that turned up when I interrogated how they use it.
What Uncertainty Buys a Rating System
Glicko, Glicko-2 and TrueSkill all track how sure they are of a rating. What that second number does to a prediction, and whose uncertainty moves it.
Deduplicating the Result Is Not Deduplicating the Work
A graph walk that collects into a set returns correct output while still enumerating every path. Why a visited set and an accumulator are two different things.
How Date Inference Works, and Why Ambiguity Is the Problem
Guessing a strptime format from examples is a scoring problem with ties. The dangerous outputs are the wrong guesses that still parse cleanly.
Bradley-Terry: Maximum Likelihood Ratings on an Elo Scale
Bradley-Terry fits every comparison at once instead of nudging after each game. Adding it to elote, and the four design choices that made it usable next to Elo.
Rating Systems Compared: Choosing the Right Algorithm
A head-to-head comparison of Elo, Glicko, TrueSkill, DWZ, Colley Matrix and other rating systems. Know when to use each algorithm.
Ensemble Rating Systems: Combining the Best of All Worlds
Combine multiple rating algorithms like Elo, Glicko, and TrueSkill to get better predictions. Learn how Elote's ensemble approach works.
The Colley Matrix: A Linear Algebra Approach to Ratings
The Colley Matrix uses linear algebra to solve for optimal ratings simultaneously. Originally designed for college football rankings.
The DWZ Rating System: German Engineering for Chess Ratings
The Deutsche Wertungszahl (DWZ) chess rating system combines German precision with practical considerations. See how it works with Elote.
TrueSkill: Microsoft's Rating System for Xbox Live
How Microsoft's TrueSkill rating system uses Bayesian inference for Xbox Live matchmaking, and how to implement it with Elote.