Chess Resources
Everything you need to understand chess ratings, tournament systems, and calculations
Rating Systems
FIDE Rating System
The FIDE (World Chess Federation) rating system is the official rating system used internationally. It uses the Elo rating system with specific K-factors based on player experience and rating level.
- K=40 for players new to the rating list until 30 games
- K=20 for players rated below 2400
- K=10 for players rated 2400 and above
USCF Rating System
The United States Chess Federation (USCF) uses a modified Elo system with additional factors including bonus points and rating floors for established players.
- Variable K-factor based on rating and number of games
- Bonus points for exceptional tournament performance
- Rating floors prevent established players from dropping too low
ECF Rating System
The English Chess Federation (ECF) uses a unique grading system that differs from Elo. Grades are calculated based on the average performance in games.
- Grades range from 0 to about 280
- Approximate conversion: Elo ≈ 7.5 × ECF + 700
- Updated monthly based on tournament results
Online Ratings
Online chess platforms use their own rating systems, often based on Glicko or Glicko-2, which account for rating uncertainty.
- Lichess uses Glicko-2 with rating deviation
- Chess.com uses modified Glicko system
- Online ratings typically run 200-300 points higher than FIDE
Tournament Formats
Swiss System
The most common tournament format where players are paired based on their current tournament standing. Players with similar scores face each other, and no player faces the same opponent twice.
Advantages:
- All players play all rounds
- Fair pairings based on performance
- Works with any number of players
Tiebreak Systems:
- Buchholz (sum of opponents' scores)
- Sonneborn-Berger
- Direct encounter
Round Robin
Every player faces every other player once (single round-robin) or twice (double round-robin). Common in elite tournaments and championships.
Advantages:
- Most fair format
- Clear standings
- No pairing luck factor
Limitations:
- Limited number of players
- Requires many rounds
- Can have dead games at the end
Knockout
Players are eliminated after losing a match. Used in World Championship cycles and creates exciting, high-stakes games.
Format Details:
- Mini-matches of 2-4 games
- Tiebreaks with faster time controls
- Armageddon as final tiebreak
Characteristics:
- High pressure situations
- Clear winner emerges
- Fewer total games needed
Chess Terminology
TPR
Tournament Performance Rating - The rating level at which you performed in a specific tournament.
K-Factor
The maximum rating change possible from a single game. Higher for new players.
Buchholz
Tiebreak system: sum of all opponents' scores in the tournament.
Norm
A performance requirement for achieving chess titles (GM, IM, FM).
Rating Floor
The lowest rating an established player can drop to, preventing sandbagging.
Provisional Rating
Initial rating for new players, subject to larger changes until established.