The calculation of ECF Grades on a monthly basis

The ECF Board have decided to institute monthly grading lists. I have advised and after consultation with members, the Board have accepted that an Elo system would be the most appropriate base algorithm. This base is amended to support ECF graded chess requirements.

The new monthly grading system will start on the 1st January 2020, but will not be effective till September 2020 at the earliest. The existing 3-digit system will remain for ECF grades for the moment and will be effective till the changeover. The grading team will confirm the changeover date in due course when the new systems are ready, and the administration process and algorithm have been confirmed to be robust.

Calculation routine
1. Working back from the January 2020 list the grading team will extract the latest published grade for all players with a grade in categories A-F in the published list and the previous 6 half yearly lists. The latest published grade for all players will be converted using the formula:  new = 7.5*old + 700. These grades will be treated as qualifying grades.

2. Each month, all previous monthly lists going back 6 periods (or till 1st January 2020 if later) will be recalculated to include late reported and amended results. Late reporting will be accepted and included for grading for those months. A restriction will be that results up to 31st December and up to 30th June will be required to be submitted within 14 days of the end of the month.

3. All results dated in the last month are collected and current grades assigned to each player. Each result is considered for a player point of view with each opponent.

4. The grading formula is –

R1 = R0 +k(W-We)

Where R0 is the grade for the previous month, k is 20 or 40, W is the player’s total score for results in the month, We is the expected total score based on the FIDE table 8.1b at

5. Where a player had submitted less than nine results (ignoring the dummy result) before the month they will hold a partial grade. This grade will have no standing outside the grading calculations.

6. Each new player in standard play will be deemed to have one dummy result – a draw with an 1800 graded opponent which is used in their initial grading.  In rapid chess the result will be against a 1700 graded player. Where age is defined as year of first result less year of birth, these dummies will be reduced by 100 for each age less than 18.

7. Partial grades will be used for grading games for the month of calculation. The partial grade is calculated as the average performance of all results to date, including the dummy result. Performance is calculated using the average of opponent’s grades in the month played and adding or subtracting points using table 8.1a in ;p being total of results/number of results rounded to 2 decimal places.

8. Each month results of players with partial grades will be used to reevaluate their partial grade as an interim grade. Then qualifying grades and these interim grades will be used in the calculations set out in 4 and 7 above. Those now with nine or more results will receive a qualifying grade based on the calculation set out in 7 above.

9. The k factor will be 20 except that in a month where a junior player has outperformed Elo expectation, then the k factor will be 40.

10. Where a grade is less than 100 it will be increased to 100.

11. Where the number of results assessed in the month exceeds 700/k, then the k-factor is limited to 700/number of results.

12. Following each June list, the grading team will review the outcome of this methodology. If the average grade appears to be trending or the dispersion of grades is changing, then they may change the parameters going forward. The first choice change will be to the special junior k-factor. They will also review the timetable with a long term objective of speeding up the process.

— Brian Valentine, Manager of ECF Grading – January 2020