This section probably contains the term "I" all too often, for which I apologise. I am afraid to say that this system probably reflects my idiosyncracies far more than is appropriate. I also apologise for this.
Before I begin this explanation, it will be as well if you note that I am, possibly, an extremely sad individual (in the colloquial British sense of rather dull, technically inclined, mathematically keen, etc.) and probably more than a little bit potty (again in the British sense of borderline-insanity) to have embarked upon this rather excessively-technical algorithm. No doubt there are simpler and more approximate methods which would be more appropriate for what is, after all, a constantly-fluid and estimation-based system. However, I got carried away doing logarithmic calculations at 1 in the morning, and you see the result.
Paul Callaghan started this process by suggesting that given our recent influx of beginners, it was time we had a more formal system for considering improvement, so that we could measure progress, and to encourage people to improve. There seemed to be a concensus that this was a good idea and that the new website I was developing meant that such a "ladder" or system would be easily displayed. I therefore felt a certain responsibility to get on with it. I also thought that the mathematical complexities of it sounded highly interesting, so I started looking and thinking.
My first source of information was the old BGA Handbook which recommends an approximate scale for internal club ladders. As a mathematician, I dislike "jagged" scales like this when one could approximate them with a smooth function. As such, I set out to find one. The miracle of Excel's graphing function, a bit of trial-and-error, and an enjoyable couple of hours prodding later, I had a function displaying that "c" (my then-arbitrarily named rating) was equal to 70 timesed by 1.155 to the power of 0.71 times "k", where "k" is your kyu rating on a scale such that 4d is +4, for instance, and 15k is -15. Yes, I know, there's an inconsistency there, because there should only be a gap of one between 1d and 1k, where there is no "zero-point". At some point I may fiddle with the system further to remove this. I am embarrassed to say that I had forgotten about it, and I have yet to decide on how to remove it. I hate inconsistencies like that!
I will write more on this subject eventually, but for now I hope that you will accept that it is based on a logarithmic scale approximating to the description in the Old BGA Handbook.
And the name? A silly pun on Simon Shiu's name, and the fact that it's a form of "stepping" up a ladder.
This description was written by Edwin Brady, the original creator of the Durham Go Ladder
For more information about the club, please email the Exec.
For questions, comments and suggestions on this site, please email the current maintainer, Andrew Ambrose-Thurman.