The improvements of rating deviation in Glicko-2 system

This article mainly talks about the differences in the calculation method of rating deviation (RD) between the Glicko and Glicko-2 systems and how they affect the players rating differently. In addition, it also includes the logician of the Glicko-2 and how it operates in real situation. In Glicko-2, the change of RD is based on more information contained in one match unlike Glicko which is just based on the play counts. In addition, the Glicko-2 solves some problems presented in the Glicko and gives players better game experience, and rationalizes the players data, makes an improvement of Glicko. This article includes detailed explanations, by using some examples and figures of functions, illustrate the relationship between RD and the difference of rating, opponents RD, and the players RD itself, also give some examples of how the mechanism of calculating RD is used in other cases, like the game Tetr.io. Thus, this paper underscores the importance of new ideas in the Glicko-2 system.