Robi and all,

I would like to say something about the ratings numbers. The numbers quoted for both setups under different rating system don't seem to point to one outcome.

Actually

The US DPN says

F16 UNI 66.4
F16 Slp 65.3

= sloop is projected to be faster then uni by 60 sec / hour bouy racing

Texel 2005

F16 Uni 100 by 104
F16 Slp 102 by 102

= Sloop is projected slower in light airs by 72 sec/hour and the sloop is projected faster in heavy winds by 72 sec/hour


ISAF (SCHRS)

F16 Uni 0.98
F16 Slp 1.02

= sloop is projected slower than uni rig in all conditions by 144 sec/hour


Australia VYC

No F16 ratings yet only Taipan 4.9 with spi corrections.

F16 Uni 76.5 * (1-0.031) = 74.1
F16 Slp 74.0 * (1-0.031) = 71.7

= sloop is project faster than uni-rig in all conditions by 120 secs/hour bouy racing.


So the bigger rating systems in the world are definately not in agreement with eachother.

And in the case of the VYC rating we must realize that the F16 uni was boosted a little relative to the F16 slp to make them more equal.

In the beginning of the class (2001) we worked on the rules with the knowlegde that the Taipan 4.9 uni's (no spi) could hold the sloops on short courses and in light to medium winds. So we trusted that the extra width, the larger square heads and large mainsails would help the uni's gain some ground on the sloops.

Of course a singlehander is always disadvantaged in the really strong winds, there is nothing we can do there but in light to medium conditions I think we'll find that the two are too close to one another to make first-in-wins unfair. Afterall even the ratings who can't agree on which is faster don't put the two (on average) further part than 99 seconds after a full hour of racing. And that is mostly because ISAF (SCHRS) rates the uni so much faster, I think that ISAF is not correct in this. Both Texel and D-PN only put the two setups about 66 seconds apart per hour racing.

In engineering and statistics we call this inconsistancy between the ratings natural noise. It is most likely caused by natural swing in the basic data used to produce the rating numbers. Compare it to this. Throw a dice 10 times and take the average of the outcome. Do this experiment 10 time in itself. When you will plot the averages you will find that probably none of the real averages is equal to its theoretical average of 3.5 and you will probably find a few averages at 2.5 and 4.5. This is natural swing in the numbers caused by chance happenings. Ratings system by necessity suffer in the same way.

I'm sure that if Gary sailed his F16 uni in the USA instead of AUS that the US d-pn for the uni would be faster than the slp. But then again if by chance Daniel van Kerckhof was born in the USA over AUS than the slp would probably be rated faster again. So here are your chance happenings that may influence the rating numbers.

I think there is only one real conclusion that can be made from the rating systems are they are now. The theoretical difference between the boats is too little to be of significance. If it was significant enough than all rating systems would at least agree on the direction of the inequality and only haggle over the magnitude of the gap.

Once again my personal experience don't point either way either. Personally I think Texel is probably best. A small advantage in light winds and a small disadvantage in the heavy stuff with on average the same performance AROUND THE COURSE. That is certainly how it feels like to me

Wouter