A competitive game in which a user and an opponent participate is executed, and a rating based on a match record of the competitive game is stored. When an update condition that, after last update, the user wins the competitive game a predetermined number of times that is two or more or the user loses the competitive game a predetermined number of times that is two or more, is satisfied, a temporary change amount of a rating parameter is calculated on the basis of a match record of each competitive game until the update condition is satisfied this time after the last update. If the temporary change amount is equal to or larger than a predetermined threshold, the temporary change amount is determined as a change amount of the rating parameter, and if the temporary change amount is less than the predetermined threshold, the threshold is determined as a change amount of the rating parameter, and the rating is updated.