# How does the Glicko rating system correlate to Elo?

I was wondering what the "rating" difference was in the Glicko, and Elo rating systems. Are they close to the same amount/number, or do they heavily differ?

Elo and Glicko are mathematical theories about how a rating system can be implemented. Neither of them define all the details of a rating system implementation, hence there is no reason what so ever for two randomly chosen rating systems to correlate with each other even if both use Elo.

For example the British Othello rating system and the English Chess rating systems are both based on Elo, yet there is little correlation between them.

Therefore it not sensible to ask "How does the Glicko rating system correlate to Elo?", but you could ask how a given implementation of Elo relates to a given implementation of Glicko.

The basic rating calculation could be the same but in Glicko there is rating deviation.

The problem with the Elo system that the Glicko system addresses has to do with the reliability of a player’s rating.

The Glicko system therefore extends the Elo system by computing not only a rating, which can be thought of as a “best guess” of one’s playing strength, but also a “ratings deviation” (RD) or, in statistical terminology, a standard deviation, which measures the uncertainty in a rating (high RD’s correspond to unreliable ratings).

Have a look on the link in the Glicko.

Also check on a very nice info about the Rating of Chess Players by Arpad Elo. I should buy a printed book of this.