 The current system in the United States includes a bonus point scheme which feeds rating points into the system in order to track improving players, and different K-values for different players.Some methods, used in Norway for example, differentiate between juniors and seniors, and use a larger K factor for the young players, even boosting the rating progress by 100% for when they score well above their predicted performance.Rating floors in the United States work by guaranteeing that a player will never drop below a certain limit.