The manual method
An obsolete method for the conversion of n to N scores consists of incrementing the number of matchpoints by 1
for every missing score, i.e.
where:
- Sn = the number of matchpoints from a normal calculation with n scores
- SN0 = the resulting increased number of matchpoints.
We express this in percentages P
n en P
N0, and multiply left and right by 100, obtaining:
(2N - 2) PN0 = (2n - 2) Pn + 100 ( N - n) |
| (2) |
Hence:
PN0 = (Pn − 50) · |
n−1
N −1
|
+ 50 |
| (3) |
Compared to Neuberg
PN = (Pn − 50) · |
n−1
n
|
· |
N
N −1
|
+ 50 |
| (4) |
a factor of N/n is missing from the difference with 50. The method pulls the scores too close to 50%
and this effect is larger the more N/n is larger.
A simple example:
a fouled board where 7 scores are to be split in two groups, of
3 and 4 scores, respectively.
According to this method the top with 3 scores is 66.7% and with 4 scores 75%.
With Neuberg we would have found: top with 3 scores 88.9% and with 4 scores 93.8%.
That is quite a difference. It is even better to proportionally stretch the scores to a top of 100%, than
to use this method.
Before the advent of the computer this method was generally used. As we see, mistakenly.