Article by Nick Doe

EBU procedures, which apply in EBU events, and are recommended for other events, apply as follows.

In general, if a board is played in two different versions, each version is match pointed separately. However, the aggregate match points for the two versions must be the same as for the other boards.

The match points which a competitor gets are arrived at by the following formula:-

(M x E) + (E - A)
A

where:-

M is the match points which the competitor would have scored considering his group only, i.e. had the board been due to be played the number of times it was in the version in which he played it

E is the total number of scores expected on the board

A is the actual number of scores obtained on the board

Scores are rounded to the nearest 0.1 of a match point (0.05 being rounded towards average).

It is probably best to illustrate with an example. Say each board is played 10 times, but one board is fouled so that it is played 7 times in one form and 3 times in another.

The normal top on a board (for the boards which have not been fouled) is 18 and the match points for each board total 90 (in each direction).

For the group of 7, a top considering the group as a whole would be 12. E = 10; A = 7. You apply the formula to the match point results arrived at using a top of 12. For ease of illustration, say that there are seven different results. The formula works as follows:-

Original match points for the group	Formula	Result (rounded)
12	123/7	17.6
10	103/7	14.7
8	83/7	11.9
6	63/7	9.0
4	43/7	6.1
2	23/7	3.3
0	3/7	0.4

 

The total is 63 (which, as you would expect, is the average (assuming 10 results) multiplied by the number of results in the group)

For the smaller group, a top for the group is 4, E remains at 10, and A = 3. So it works as follows:-

Original match points for the group	Formula	Result (rounded)
4	47/3	15.7
2	27/3	9.0
0	7/3	2.3

The total is 27 (again, what you would expect).

The total for the whole board is 90, and an exact average in both groups is 9, as it would be for the unfouled boards. Obviously, you won't get seven different results in the larger group very often, but the formula works for any series of match points in the group concerned.

We apply the formula regardless of the size of the groups, unless the board has only been played once in its fouled condition, in which case it is regarded as unplayable. If it is unplayable, the Laws require an "artificial adjusted score" to be awarded, i.e. average plus to a pair not at fault, average to a pair partly at fault, and average minus to a pair at fault.

If the board has been played in its proper form on all but one occasion, then, strictly speaking, the formula is applied to the larger group exactly as previously. Thus, with ten results expected but only nine achieved, the match points would be 17.9, 15.7, 13.4, 11.2, 9.0, 6.8, 4.6, 2.3, 0.1, a total of 81 (90 less the average the other pair is going to get). In practice, it is an acceptable alternative for a club, particularly one which scores manually rather than by computer, to use a much simpler formula when there is just one result missing. This is to reduce the top by one, increase the bottom by one, and score normally with that revised scale - again the total is 81.

Whether the club uses the EBU formula or the simplified version for cases when just one score is missing, is a matter for it. It should, however, be consistent, as it will be appreciated that the presence or absence of fractional match points could make the difference between a tie and not a tie, which could affect the destination of Master Points, trophies and prizes (if available).

If you score by computer, any reputable program will do all this for you without you even noticing, and of course it will do it consistently.