2.6.4 How we do it.

At the time of writing (2000-12), the database contains about 9500 games and the history of busy tournament practice is not older than two or three years. This is not enough for a reliable dynamic rating. Therefore, we still use static rating.

In order to devalue the games more slowly than ELO, we use a function, which mimics the devalue-function of ERIK VAN DEN BERG (Bombbrief 14.). He stated score weights of 1 : 0.8 : 0.55 : 0.3 : 0.05 for scores after zero to four years. A least squares fit of a GAUSSian function yields a time constant of 2.5731 years.