Understanding the DWZ
Short explanations of the German Chess Federation's rating regulations — every statement with a citation, every number from the same calculation engine as the forecast.
- How the DWZ is calculated
The formula Rn = R0 + K·(W − We) step by step: expected score, K-factor, rounding, floor — with an example from the calculation engine.
- The K-factor (development coefficient)
K = K0 · b + a: base value by index and age, brake factor for losses below 1600, success bonus for juniors — the full table from WO Appendix 1.3.
- Tournament performance and special rating
When an opponent is rated with their tournament performance instead of their DWZ (WO 3.6): performance rating, the 300-point rule, the exception for two-player matches.
- Initial DWZ, unaffiliated players and foreign ratings
Who gets a first DWZ and how it's calculated (WO 3.4), why unaffiliated players don't receive a DWZ (WO 3.4.3), and when FIDE Elo counts as a foreign/converted rating (WO 4.1.2).
- How accurate is the forecast?
We automatically compare our forecasts with the official DSB evaluations — this page covers the method and current figures.
- DWZ and FIDE Elo compared
Correlation, regression and bin tables from the public DSB list — aggregates only, no converter.