| |  Re: F18 new rating
[Re: ksurfer2]
#253648
10/18/12 08:37 PM 10/18/12 08:37 PM |
Joined: Jun 2001
Posts: 3,116
Annapolis, MD Mark Schneider 
Carpal Tunnel
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Carpal Tunnel
Joined: Jun 2001
Posts: 3,116
Annapolis, MD | Ksurf
You are correct.... Your point is valid for portsmouth systems. Each data point is dependent on the other boats in the fleet. So... you have to make sure the basic assumptions for the race were met... All boats were in Active one design classes, all boats in racing form with race sails, etc. The N20 class has stopped one design NAs.... so... you could expect the PN rating to drift higher relative to the fleet. This is a problem.
The measurement systems have to decide whether the formula is useful in the real world... IE do the ratings reflect reality. Ie optimal potential... If they don't ... the formula needs work. Since the N20 measurement specs have not changed.. the formula would not have been adjusted.. However, development of better square top sails, longer High aspect boards and low boat weighs were measured factors that the formula did not consider. Also the top sailors world wide race in this fleet. The results on the water indicated the F18 was faster then original SCHRS rating by 5%. A lot of work was done to determine how much faster then the old rating and how the formula should evolve to handicap all cats to have as level a playing field as possible with a single measurement formuula. This adjustment process is very different then your example of classes loosing their racing form and then adjusting their rating higher.
Last edited by Mark Schneider; 10/18/12 08:41 PM.
crac.sailregattas.com
| | | Re: F18 new rating
[Re: Mark Schneider]
#253657
10/19/12 08:42 AM 10/19/12 08:42 AM |
Joined: Dec 2011
Posts: 108 franck
member
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member
Joined: Dec 2011
Posts: 108
| Franck
I would encourage you to read the documentation provided by SCHRS for the 2012 revision. You seem to be about two years out of date....
In fact the problems with the real world use of the measurement rule led the french to actively participate in the modifications to the table published in 2012.
For your info, the SCHRS never test the formula on real world.
It was only calculation based on measurable dimension of boat.
A necessary bad, but not so bad system, with two major difficulties:
This is not true.... both SCHRS and Texel check their formula against real world results... The rating is only derived from measurable dimensions and the formula is adjusted. The formula is crystal clear because it is public and uniformly applied. The effect of weight, windspeed, boat weight and fleet strength are legit issues and the committee makes tradeoffs to match the formula's accuracy to the real world as best as possible. We have no tablets from God as to the divine formula. Your major issue is the Sport of the game. Handicap racing will not be as accurate... the precision of the handicap game is not the same. The 2012 SCHRS table is IMO fair. Where you use handicap racing depends on many factors.
RE SCHRS and F18s and Sport
In the USA, we have few regions that get a critical mass of F18's on the starting line for that regions major regattas. We are not as fortunate as you euro's... Pitchpole and myself argued that racing on handicap at both local and regional events will get a larger fleet of boats racing and this is preferable to 2 or three boat one design starts. In the end... we need every boat on the line we can so that we cover the costs of regattas. Pitchpole and myself believe that two or three boat One design classes (which we will run) don't maintain interest or grow the sport in our regions.
Mark, My text is in two part, The first part is considering SCHRS before there I'm sure that rating were based 100% on a formula, it as existed a SCHRS calculator on the website, don't you remember ? And the main issue was the weight crew (75 kg per crew) for calculation purpose only. Nobody's never been cheking weight crew in a regatta using SCHR rating ? The only reason was the compliance in some class rules (F18, HC16 ...), The second part considering the implementation of performance, I confirm that this system has been proposed then postponed by the french MNA and now SCHRS is the front line. Rating is necessary with little fleet, as our greek friend said: it's a necessary bad... Have fun and courage for your work that is necessary. | | | Re: F18 new rating
[Re: christos]
#253708
10/20/12 03:37 PM 10/20/12 03:37 PM |
Joined: Jun 2001
Posts: 3,293
Long Beach, California John Williams
Carpal Tunnel
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Carpal Tunnel
Joined: Jun 2001
Posts: 3,293
Long Beach, California | As long as your Tiger is Hobie Class legal, yes.
John Williams
- The harder you practice, the luckier you get -
Gary Player, pro golfer
After watching Lionel Messi play, I realize I need to sail harder.
| | | Re: F18 new rating
[Re: christos]
#253736
10/21/12 05:30 AM 10/21/12 05:30 AM |
Joined: Dec 2011
Posts: 108 franck
member
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member
Joined: Dec 2011
Posts: 108
| Hobie Tiger as ISAF class does not exist in SCHRS table (as far as I know it has never existed). "Hobie Tiger F18" is the "Class" rating = 0,966 check there: http://www.schrs.com/ratings.php
Last edited by franck; 10/21/12 05:54 AM.
| | | Re: F18 new rating
[Re: christos]
#253773
10/22/12 02:00 PM 10/22/12 02:00 PM |
Joined: Dec 2011
Posts: 108 franck
member
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member
Joined: Dec 2011
Posts: 108
| http://www.schrs.com/rules.phpB.1 Quality of boats
These rules are created mainly for production boats.
Non-productions catamarans, experimental boats and new types with provisional rating may be ranked apart.
B.1.1 Production boats
A production boat belongs to a registered class or to a registered type.
........
B.1.2 Non-production or experimental boats
A non-production boat is any boat which does not belong to a registered class or to a registered type. A boat built as a registered boat but which is modified in such way that she contravenes her class rules will be considered as a non-production boat.
B.2 Rating certificate
To be permitted to race, a boat shall provide a rating certificate issued by the ISAF or a National Authority.
........
D. MEASUREMENT
All measurements must be undertaken according to the ISAF measurement rules and instructions.
For "Formula" type classes such as Formula 16, Formula 18, Formula 20 and A-Class, the rating is to reflect the limiting values for all relevant measurements permitted by the class rules. Where a measurement is required by SCHRS but not governed by class rules it is necessary to carry out measurement as required for an SCHRS rating.
When I read that I think it is the same F18 rating for F18 Tiger or F18 Phantom. May be I'm wrong.
Last edited by franck; 10/22/12 02:07 PM.
| | | Re: F18 new rating
[Re: christos]
#253775
10/22/12 02:13 PM 10/22/12 02:13 PM |
Joined: Mar 2009
Posts: 932
Solomon's Island, MD samc99us
old hand
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old hand
Joined: Mar 2009
Posts: 932
Solomon's Island, MD | That would appear accurate. Remember as late as 2010 the Tiger was still a competitive platform, with new boards and sails (and maybe rig). I think the issue is more related to the sailors on the boat, fast sailors are on more modern platforms. Of course the fact that the rating drop applies to all boats may not be fair but measuring your individual boat may not really be viable. We have an ARC22 in our fleet and I think they are using a N20 rating right now, and we're under SCHRS.
Scorpion F18
| | | Re: F18 new rating
[Re: franck]
#253794
10/23/12 05:05 AM 10/23/12 05:05 AM |
Joined: Sep 2005
Posts: 893 waynemarlow
old hand
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old hand
Joined: Sep 2005
Posts: 893
|
When I read that I think it is the same F18 rating for F18 Tiger or F18 Phantom. May be I'm wrong.
Take one thing on the boat outside class rules, perhaps something as simple as change your downhaul to differnt system and you have a unique experimental boat | | |
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