Glicko Rating System
Understanding our skill-based rating system
Guess Games uses the Glicko-2 rating system to provide accurate and fair skill ratings for all players. This advanced rating system, developed by Mark Glickman, is widely recognized as one of the most accurate methods for measuring player skill in competitive games.
The Glicko rating system is an improvement over the traditional Elo rating system, designed to address its limitations. Unlike Elo, which assumes all players have equal uncertainty in their ratings, Glicko introduces a Rating Deviation (RD) that measures the confidence in a player's rating.
- More accurate skill assessment than traditional Elo ratings
- Accounts for rating uncertainty through Rating Deviation
- Adapts quickly to changes in player performance
- Handles inactive players by increasing uncertainty over time
- Provides fair matchmaking based on skill level
Initial Rating
New players start with a rating of 1500 and a Rating Deviation (RD) of 350. The RD represents uncertainty about the player's true skill level.
Rating Updates
After each game, your rating is updated based on your performance, your opponent's rating, and both players' RD values. Beating a higher-rated opponent increases your rating more than beating a lower-rated opponent.
Rating Deviation
As you play more games, your RD decreases, indicating increased confidence in your rating. If you don't play for a while, your RD increases to reflect uncertainty about your current skill level.
Volatility
The system also tracks volatility, which measures how much your rating tends to fluctuate. Players with consistent performance have lower volatility, while players with variable results have higher volatility.
Rating (μ)
Your skill level, starting at 1500. Higher ratings indicate better skill. Ratings typically range from 1000 to 2000+.
Rating Deviation (RD)
Uncertainty in your rating, starting at 350. Lower RD means more confidence in your rating. RD ranges from 30 (very confident) to 350 (very uncertain).
Volatility (σ)
How much your rating fluctuates. Lower volatility means more consistent performance. This helps the system adapt to your playing style.
- More accurate skill representation than simple win/loss records
- Fair matchmaking by considering skill uncertainty
- Quick adaptation to improving or declining players
- Handles new players appropriately without penalizing experienced players
- Provides meaningful comparisons between players of different activity levels
- Glicko-2 Rating System (Mark Glickman)The original paper describing the Glicko-2 rating system by Mark Glickman.
- Glicko Rating System - WikipediaWikipedia article providing an overview of the Glicko rating system and its history.
- Understanding Glicko RatingsAn accessible explanation of how Glicko ratings work in practice, using chess as an example.
Guess Games implements the Glicko-2 rating system with default values: initial rating of 1500, initial RD of 350, and initial volatility of 0.06. Ratings are calculated separately for each game, and players also have a global rating that averages their ratings across all games. The system uses a tau (Ï„) value of 0.5 to control volatility changes.