The construct of each rating system is based on relative performance of each boat to a single reference. It is not required that such a reference is an actual design or class but that does have its benefits.

The old standard was 100 and was assigned to the Tornado under Texel although the true reference was the H16 at 116. The number 116 was taken because that was the numbers use for the H16 in an older rating system. Such are considerations of legacy. Sailors soon forget to origins of such things and therefor following up on legacy benefits is useless.

Yardsticks in general use funny numbers. Often somewhere between 50 and 80 or between 110 and 160. Such choices result in unnecessary calculations and also in corrected times that have no meaning.

If a design with rating of 70 sails for 60 minutes and is corrected to 42 minutes and looses to a boat with a 41 minutes corrected time many sailors think that the first boat had to sail 1 minute faster to win.

This is wrong as 41 * 100/70 = 58 min and 34 second. Or 1 min and 26 secs to slow to win. An increase of 50 %

It is MUCH MUCH smarter to assign a rating of 100 to the most prolific design. Arguably this is, or will soon be, the Formula 18 class.

Than NO handicap calculations need to be performed on the F18's, their elapsed time is also their corrected time. Less potential for errors as well.

In addition a 110 rated boat sailing 60 minutes with corrected time being 54 min 33 sec; that was beaten by a F18 coming in at 54 min, had only to finish at 54*110/100 = 59 min 24 seconds to win. Or 36 sec faster. As you can see this very closely approximated by the 33 second in the corrected time results.

So keeping all ratings as close to the reference of 100 is very beneficial. Centering this rating 100 among the group of boats most often entered in races makes comparison alot more easy to both the sailors and RC's. The F18 class is neatly centred between the F20, Tornado's and A-cats on one side and the bulk of the (older) 16,17 and 18 footers on the other. Neatly being defined here as being proportionally closer to the classes that will see most boats enter => F20's, Tornado's, F18's, F16's, A-cats and the faster Hobie's and Nacra's of the past.

For these reason choosing the F18 as the reference class has many advantages. And therefor we choose to do so.

Wouter