A Competitive Hub for the UK Age of Sigmar Community

The Elo system is an algorithm which determines the relative skill level of a group of players by constantly adjusting ratings based on match outcomes. It processes individual matchups on a per-round basis rather than tournament results, and considers only the relative skill of players. Elo is designed for games like AOS, but without computer assistance can be very challenging to manage. 8Realms solves this an with automated, nationwide rating.

8Realms only considers individual match performance when calculating skill levels, which has a number of benefits:

• Your rating is unaffected by event size – how you perform in your matchups is all that matters
• Events with high average skill levels do not disadvantage players – lower skilled players will be rated only on their own match outcomes, and higher skilled players will be rewarded for hard fought victories even if they don’t finish on the top table
• Higher skilled players cannot ‘game’ the system by deliberately attending events with low average skill – repeatedly beating lower ranked players has a limited effect on rating
• Simply attending a lot of events does not improve a player’s rating – if you play less frequently, you will not be overtaken in the ranking by a lower skilled player, even if they played competitively full time
• Lots of other useful analysis builds on your 8Realms rating, including ‘performance ratings’ which can quantify how tough an event is for you personally, and identify event MVPs who performed the best against the toughest opponents

The main limitation of the 8Realms system is that it requires quite a lot of matches before a player’s rating can be considered ‘truly’ accurate. Typically an Elo system requires a player to complete around 25 matches before their score is considered truly accurate, which is why some 8Realms ratings are italicised and marked as provisional when the player has not yet completed enough games to have a ‘true’ rating. This doesn’t mean that an italicised rating is inaccurate, as this does reflect a player’s performance, it just means that the underlying maths has not yet provided a high enough confidence level to be sure. However, many players will take several months to achieve a ‘true’ rating.

A second limitation of the 8Realms system is that like all Elo systems it technically only measures relative performance. This means that if a population (ie all UK AOS players) are significantly better than average players, then your rating will be lower than for an average player. This doesn’t really matter for something like a UK ranking system, as long as all players in the population are included – which for 8Realms, they are. However, this means that an 8Realms UK rating cannot be directly copmared with an Elo rating for another population, such as US players.

The main benefit of ratings for players is to provide an accurate reflection of your skill. This makes it easier to seed tournaments, and also to select for teams and invitational events. Many implementations of Elo are different, so it’s important to refer to your rating as an 8Realms Rating rather than just “Elo” so that people know what specific algorithm is used.