These ratings for Tarrasch, Siegbert are calculated yearly, as of January 1st of the indicated year. Each yearly rating incorporates all rated games played in the preceding year, along with the ratings that were already calculated at the start of that year. Players' initial ratings, once they qualify with enough games, are based on all games played during the preceding year against rated opponents. Each year, everyone's rating on the January 1st list has been increased/decreased by an identical amount, so that the average rating of the #8 through #12 players is aligned at 2600.