K-factor changes: recent implementations

When does a player’s K-factor change (Regulation B.02.8.33):

• If a player’s K-factor is changed due to reaching 30 games, this change will take effect for any tournaments rated after the 30-game total is reached.
• If a player’s K-factor is changed due to reaching 2400, this change will take effect for any tournaments rated after the 2400+ rating is published.
• If a junior player’s K-factor is changed due to reaching 2300, this change will take effect for any tournament rated after the 2300 rating is reached.
• If a player’s K-factor is changed due to a player reaching 18 years of age, this change will take effect for any tournaments rated after 1 January of the year following the player’s 18th birthday.

Changes in a player’s K-factor are not reversible, and remain in place, even if a player’s subsequent rating falls below the cut-off for the change.

How it is now being implemented:

During a review of the FIDE Rating System, it was discovered that there was a discrepancy between how a player’s K-factor changes upon reaching 30 games, and how a player’s K-factor changes upon reaching a certain rating level. This has now been corrected to make the changes to a player’s K-factor consistent. This change took effect for the September 2023 Rating List, and ratings have been recalculated with the correct code. It is not possible to amend earlier rating lists as these could affect title and norm calculations from previous events. In certain instances, a player’s rating may be different from what was initially published for the September 2023 Rating List.