Disappointment Reigns .. but, on the other hand, there's a corresponding amount of happiness out there somewhere
On 8/11/2015 2:14 p.m., somebody@xtra.co.nz wrote:
> (name and phone number with-held) sent a message using the contact form at http://www.compassmate.bridge-centre.org/contact.
>
> I would like an explanation please as to why my partner and I dropped such a considerable percentage form our Club result. I do use Compass frequently and realise there are scoring differences but find the outcome from Friday completely unfathomable. We also don't seem to appear on the scoring of the non aggregate E/W result.
> I will really have to consider playing this event again...one I have supported for many years.
>
Our reposte ..
We-ell, Somebody .. it's like this:
You've watched X-Clubs results long enough to know that there can be massive swings in comparing club results (especially when there are only a very small number of tables playing - something you're maybe not so used to) with the answers coming out over a large number of tables. With only six tables your score can be a maximum of 10 for a top or one of six gradations between 0 and 10. You might score 100% as the best score out of the six by posting a score that would rank only 400th, say, out of the 485 tables we scored. That's how your 100%'s can turn into 82%'s.
We worked out a couple of years ago that you actually need about 120 pairs before scores can be reliable enough to with +/-0.5% of what they would be if scored over a much larger population - say 1000 pairs as we have here. See the article on it at www.compassmate.bridge-centre.org/nzw04
There has always been shock/horror from small clubs at the way the scores can change. Karen Martelletti did some fine analysis on a situation similar to yours in the very early days. It is at www.compassmate.bridge-centre.org/node/29.
At the end of the day it's very simple: you get 2MP's for every pair your score betters, 1MP for every score you tie with, and no MP's for all the ones who do better than you do. The end result is calculated purely adding all these 2's, 1's, (and 0's) and dividing by the maximum score possible ... which was 23178 here.
I hope this explanation soothes your distress. We'd hate to see you go off this event after so long. But hey - look on the bright side - next year your score is just as likely to go UP!!
Kind regards
Somebody Else
