[SoccerMath]

They are purely results based. The only inputs are game scores and home field advantage. Your rating depends on these results relative to the strength of the opponent in a particular game, and what result you were expected to deliver. These probabilities are determined based on the assumption the teams' quality levels form a normal distribution.

Winning is, of course the most important factor, followed by the score, with diminishing returns for increasing goal differential. The returns also diminish quickly when playing teams far worse than you. In fact, it is quite likely when playing vastly inferior teams, to lose points even with a win. Conversely, it is possible to gain points when losing to a superior team.

Let me know if you have any questions.