http://www.catsailor.com/Steeplechase/Steeple04Story_News.htm

I'll surely get flamed for this one but can anybody explain to me why the SC20, "the best designed 20 foot cat in the world and 20 year old holder of round texel record", sails of the slowest rating of the whole fleet except for two Hobie 21 sport cruisers ?

And that is AFTER being compensated for having an oversized mainsail, making the base rating 64.4 / 0.98 = 65,7 !!! Even a Hobie 20 is rated faster than that without having a spinnaker (64.9). Even the smaller F18's need to give the SC20 "Big main" over 16 minutes time in a 9 hour distance race. I dare not calculated how much they owe a standard SC20.

At least under Texel, despite its flukes, the sc20 is rated the same as the Tornado and that seems a whole lot more fair.


Ratings participating in Steeplechase in other of being quick :

-1- Marstrom 20 56.5
-2- CFR 20 58.4
-3- Tornado 59.0
-4- Nacra I-20 59.2 (US version)
-5- Formula 18 62.5
-6- Nacra 6.0 NA 62.7
-7- Nacra 6.0 NA 60.2 (with spi)
-8- ARC 21 61.5
-9- Mystere 6.0 63.9
!****!!
-9- SC20 64.1 (including a "big main" correction)
!****!
-10- Hobie 21 64.4 (with spi)
-11- Hobie 21 67.1


Wouter

Wouter,

I am sure you are aware of the portsmouth handicap system controlled and administered by US Sailing. Please refer to the US Sailing website to answer your question on how a rating is determined. They provide a detailed explaination of their system and adjustments to that system.

You appear to have made an error in your calculations. According to the published results, the boat you question sailed with a rating of 64.1, not 64.4 as you used to calculate the base number. Again, please refer to the US Sailing's portsmouth ratings to verify the base rating.

The boats performance through the years seems to speak for itself. I believe any issues about handicap rating should be directed at the handicap system itself, rather than individual boats sailing within that system.

Regards,
FP

Downloaded my GPS Tracks and looked at them over my route waypoints.
It was funny to look at the charts now with the track overlay and go "No wonder I saw branches sticking up from the water on that shoal we just missed, it's an island"
Here's the breakdown.

Surprenant/Strickland
Hobie Tiger 1530

Sat:
10 tacks/gybes (have to love a crew that can work the main in high wind)
20.2 MPH max speed
68 miles

Sunday:
106 tacks/gybes (have to love a self tacker setup)
20.2 MPH max speed
52 miles

What you have here is a perfect example of why dixie pn numbers make for a hollow victory. They seem to have figured in people using old tired sails and rigging into the numbers of old designs. also slower, less proficiant sailors in a given class yield a higher # for that class.
The # for the M20 seems awfully low considering they were beaten boat for boat by the tornado.
too bad the formula rich dutch system cannot achieve the status of being the world standard.
At least they all got together and had a good sailing session.

Lars Guck an Hans Barth win but Bill Roberts and David Weir finish first?
What is the REAL race?
First home or first on corrected?

Yes.

Wouter,
Don't forget the taller rig as well. I am not positive but beleive it carries 38' of stick to go with that main, and a 12' beam, and a spin?(64.1) I didn't see the boat but I think that is the set up. I apologize in advance if I am wrong.
ARC 21, 33' mast, 8'6" beam and spin plus 1' additional waterline comes in at 61.5. Hmmmm.

Its our own fault!!!

I mean, someone TOLD BR to build a tornado killer.... he did and NOBODY bought one.

So now there are like 3 racing. No wonder the rating on it is great.

If more if us bought SC20's the rating would stink guys! I mean cmon don't you get it?

Hey Wouter-

If you want to see a boat rating change; that particular boat must be demonstrating that it can win in sanctioned races by more than one sailor. If the data indicates the rating is off it will be fixed. Also just because Roberts wins with an SC20TR doesn't mean I could or you could. The tall rigs are a beast to sail and you have to be very experienced as well as used to the boat before you can make it go well. Is it a ratings beater??? with Roberts I say a demonstrated YES!!! If I'm sailing it possibly but definitely not a sure bet. They work extremely well in south Florida conditions but will toss you into the main if you let up a small amount. So the very nature of the SC20TR [ie old design/not sailed much by the new fast guys/not even a pic in the write up that I saw] is the reason the rating is so high/low [how ever you look at it]. Where as the T is sailed/raced all over the world everyday. Every year they re-evaluate and some of the boat ratings are changed. Its not just a formula...its how well the boat can go with several sailors demonstrating its performance across the country.

The bottom line is fast guys can make any boat go. Just check the Texel info around 25 years ago. Just look at the competitors in the pics. Every boat being pushed to the max. This is a great sport which requires more skill that brawn.

thom

Thom,

While all of what you said is true, it is noteworthy that the Portsmouth rating does not use data from distance races (to my knowledge). They only use course racing information. It is a fairly rare case when the SC20 finds it's way around a buoy course so it's rating, and a few other boat types, is a bit unsubstantiated.

I'm beginning to slowly waver regarding whether I like the Portsmouth or the Texel type rating systems. On one hand, the Texel system overcomes the big flaw in the Portsmouth system where 'rating creep' takes place when a boat is not very active or where there simply isn't enough data to support a fair rating for a given boat. On the other hand, I feel that the Texel system is a bit 'set in stone' and has to ignore countless complicated boat design parameters in order for a human being to be able to calculate a rating. Portsmouth also allows different correction factors for different wind strengths - does Texel do that?

My personal feeling as that since distance races and buoy races are so different that we may need two different rating systems for each type of race. Perhaps a Portsmouth Distance rating would be in order that would be put together based on actual race information? More and more catamaran races are turning into distance races afterall. The Tybee 500 is going to use the Texel system in 2005 and it should be interesting to see.

Gees. What's it mean???...

The race was mostly upwind...According to Rick's report.. they carried the chute for just a few miles and the Supercat did not have a chute so it has a huge rating advantage in this kind of race. You need to race apples against apples if you want to make sense of this race. Eg the Supercat and the Nacra. If they race even up... the supercat wins the legs by 20 and 40 minutes... Kudo's to Bill.

That's the way it goes in distance racing. Who won... depends on what you think the race is about. IMO, Spin boats compete against one another, Sloop rigged boats do the same. ... Or do you value the Overall corrected time winner, the role of the dice by mother nature which rarely gives you a 50 50 upwind downwind race course determines the winner. (The results won't change based on a few perecent delta on the rating.) Oh Yeah, the M20 had a substantial lead until it hit the mud! How do you factor that into your performance computer?

In this race. The trophy that matters, based on its long history, is the elapsed time winner for the Ol Lawn Chair. It is what it is and it leads the story.

Just curious - the US Portsmouth system you guys are using : It seems to me that this system promotes the designing of boats that are overpowered. ("They work extremely well in south Florida conditions but will toss you into the main if you let up a small amount")
I`m not familiar with how it all works, but it seems that such a boat will clean up in light air, then when it gets heavy and unmanageable, it will get a corrected rating for higher wind, when more manageable boats are sailing past it.
So it wins on all counts, basically.
I also think having this rating system work well relies on large fleets of all rated classes racing against eachother on a regular basis, this no longer seems to happen anywhere on the planet.
Perhaps the committee who run the system should look into removing classes from the list that are not well represented at bouys racing, if this is where they collect their data. Alternately, if these boats only show up for long-distance races, use that information. The fact that Bill Roberts is regarded by most who know him as a very good sailor would mean that, with your system, the handicap of the SC20 would actually be unfair, but not in favour of the design, rather acting against it, since your numbers are based on skipper performance as well, and Bill is the only SC sailor who races ?
It would be interesting to see what rating this boat were given by ISAF / Texel if you punched the stats of the boat into it. You could then look at averaging the two out, between ISAF & US Portsmouth. That might get you halfway to the truth, and a little closer to reality.
I`ve heard that the ARC17 Bill launched a while back is also a "ratings beater", seems like Mr. Roberts has figured out how to design fast boats that "appear" to be slower ?

Jake,

When I was still an advisor to the Texel system I worked out a new measurement based rating system that adresses all the complaints of the current Texel system. It is however just as simple as the current system. It does compensate for different beams, has two wind dependent ratings (one for sub trapeze conditions and one for trapezing conditions. It also solve the uni-rig+spi problem and cuts down on the solo to doublehanded inequality.

It is not perfect but it goes a long way in adressing all the issues that have been specified. I truly believe this system to be the superior version to Texel. It is largely based on the current Texel system but was upgraded with the experiences gained over the last years.

For distance racing I have made a plug-in to this system that allows quick and easy adjustment of handicaps for distance racing. When typing in a normal bouy race parameters it converts back to the simple 2 number upgraded Texel system. In short they are all compatible and even backwards compatible.

I proposed this system to the Texel committee but it went too far for them. They only wanted to take a reefing allegorithm into the system and one that I couldn't find myself accepting. It was just so cumbersome and distance from reality. This would have also taken the beauty out of the proposed system.

So here I am with a modified system that adresses the wishes of sailors on both sides of the Atlantic in a very easy to maintain manner. It is doing nothing right now. Although I'm thinking to make a play with to the ISAF/SCHRS organisation.

This post is intended to spread the world of mouth so that people know a better system is around and available. And it was build on the good parts of Texel and improved on its bad parts.

Any takers ?

Wouter

Actually the Texel system does not contain much formulae.

Actually I found when researching updating it that I could approximate it extremely well by three linear dependencies. It may look complicated to some but the real Texel system behaves very much just like :

Rating number : 148.92 - 2.75 * rated sailarea - 6.141 * rated length + 0.132 * rated weight

A summation of just a constant and three weighted variables.

See the picture below for the dependencies :

Texel higher order formula are in pink
The linear approximations are in blue

All graphs have been scaled to have the lines start or end at 0. So the numbers on the vertical axis are differences in ratings relative to a given constant and not actual ratings. But this is not important when looking at the shape of the dependencies. Also all constants are later combined into the 148.92 constant given above.




The blue lines are straight and the pink lines are every so slightly curved. However it will be clear that the curves are so small that it hardly matters.


So in fact calculating a very close approximation of Texel can be as easy as performing 3 multiplications followed by four additions. Not much higher math here. If you to get that extra 1 % accuracy than you'll have to perform 3 addition calculations (rise to the power ...) . All in all MUCH LESS math than involved in regressing race data to PN numbers.

Wouter

This isn't golf. The handicap should rate the physical sailboat. we have computers now. there can be 50 modifying formulas idetifing all sorts of parameters. The calculations can be done between race days, in the long winter, whenever. i'm no fan of trying to decribe nature with numbers, but the fields of areodymanics and hydrodynamics are fairly well researched by now.
The idea that so many 20 footers can have such wildly varying handicaps just can't be right. i have raced a tallrig supercat in the 80's, and they just aren't inherently slow. the regular supercat was supposed to be faster than a tornado of it's day. in a stiff breeze it was, just because of the higher righting moment... probably.
if someone showed up to a race without their rating figured out in the computer, give them one that would be leaning more toward hurting them as opposed to giving them a gift.
this is all just my thoughts and wouldn't really affect me in my current life, but maybe it is food for thought.
good sailing eh