Seahorse July 2016
James Dadd

Over the years there have been many rating rules. I include the likes of the International Rule, on which the meter classes developed as level rating classes, the RORC and CCA rules, leading onto IOR, CHS, IMS and the current crop of rules. That is just the internationally seen rules, there are many more around each country and even neighbouring clubs around the world. The vast majority rely on a single number scoring system. But several have tried multiple systems throughout the last 30 years. There have been some dramatic failures in this area, and some success.

The interesting thing is that most sailors are happy with the advantages of a single number, in knowing where you are on the virtual race course without having to consult your tablet and assume that the Race Committee is seeing the same information as you. Being able to cross the finish line and already know where on the score board you sit is always preferred. But some feel that the multiple scoring options give an additional level to the accuracy. This is something that we have continually monitored over the years to ensure that we give all competitors the full range of options they wish for. For example, there is a very simple calculation so that Race Committees can chose between time on time or time on distance scoring under IRC. We are currently asking whether event organisers want this printed on the certificate as well as the ToT default approach.

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Image: RORC/Paul Wyeth www.pwpictures.com 

We have also continued to look at multiple wind strength and course type scoring since we started the investigation into IRM back in 1998. There are several elements that need to be considered in every option: firstly, the Race Committee needs to do it right. That might sound simple, but when looking at wind ranges, the RC needs to have accurate and dedicated wind instruments around the course at a designated height above the water to be able to accurately determine the wind strength. Often the break point between light, medium and heavy are at the points most events occur. So a larger boat with wind instruments at 25m might be seeing constant breeze of 16 knots TWS and a smaller boat at 8m might see 12 knots TWS. One will think the heavy airs number is being used and the other the medium airs number. When they get back to the bar and see the scores these discrepancies can cause confusion and argument depending on who wants what. So the Race Committee needs to be extremely effective and have the resources available to them to accurately state the values. And have a thick skin and be happy to drink at another bar!

Then we come onto the rating effects themselves. Looking at a very recent event that had a fleet of 19 boats competing in 6 races over 3 weekends using multiple number scoring, there was a range of conditions with all three values being used. We ran the results as a comparison to the IRC single value and found very similar results as we normally do. But what interested me, and prompted me to write this, is the effect the of multiple number scoring against a single number using the same rating system.

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Image: RORC / Lloyd Images  www.lloydimages.com

I compared the final results against several other approaches: firstly I created an average rating from the three wind strengths and ran the results. Of the 19 boats not one had changed position in the final standing when using this method. I then ran the series using only the light airs rating and again using only the medium airs and finally only the heavy airs. This showed slight changes, of no more than one place up or down, here and there. But then I treated the combined three scores as a single 18 race series and looked at the results. To my surprise not a single boat had changed position from the single number score or the standard multiple number score.

So what was the multiple scoring solution achieving? In this particular case, with a wide range of conditions throughout the event, it appeared to be nothing. But then looking at whether it would alter the scores with a more stable weather pattern at any point in the range, again, it seemed to have very little effect, and considering that some of the numbers looked a little questionable (one boat came first one day if rated in the medium strength but 8th if scored in heavy) I suspect the effect was even less than I was seeing.

This is not the first time I have run such comparisons, but it is the first time I have seen identical results. I do not have room on these pages to talk about the different course options, but maybe next time. But in the meantime I do note that on my office wall I have a quote from Einstein that says “Everything should be made as simple as possible, but no simpler”. We have a complex sport already.

You can see the results of the study at http://www.ircrating.org/concentric-circles/497-seahorse-jul16-data