ABSTRACT
Harkness (named after its creator) was designed as a way to maintain player ratings in tournaments. Each player would enter a tournament with their former rating (new players who did not have a prior rating would be assigned a provisional rating instead, i.e., a starting number). To deal with the deficiencies of Harkness, the Elo system (also named after its inventor) was created. In Elo, a player’s prior rating is used as a baseline, and then, it is increased for each win and decreased for each loss. Hiding player ratings and using them solely for matchmaking can also help, particularly if there are other measures a player can look at, like ranking systems. In the Elo system, the expected probability of winning varies in the range of 0–1. This means that an infinitely skilled player beats an infinitely unskilled player 100% of the time.
