Tiberious wrote

TiberiusGV

A bit of history that your club CRAM and mine CRAC experienced back in the day. Our clubs used the NAMSA catamaran rating system administered by Herb Malm. US Sailing took over the Dixie portsmouth system and with Darline Hobock taking the volunteer lead made a commitment to support the multihull racing scene. Both clubs vigorously debated a move from NAMSA to US Sailing Portsmouth. I have a vague memory of speaking with Roger Cochran at the time. The core principals remain the same and are:
Accuracy
Transparency
Authority
Robustness

Accuracy How close are the ratings to the true rating of the class.
Transparency Do the rank and file racers KNOW what data and methods are used to generate changes in the ratings and do they think this process is fair.
Authority The yacht clubs and catamaran clubs want to know that they have the support and approval of regional and national bodies that can settle all disputes.
Robustness. Can the ratings quickly get to a fair rating for all of the boats that want to go racing. Recalculating last seasons results using the New... better more accurate ratings (not saying I did this....errrr ahem...) is just nuts.

Concurrently, the kind donation of the Hoyt Jolley endowment to support a multihull championship within US Sailing Adult Championship programs was a powerful incentive for most clubs to switch from NAMSA to US Sailing Portsmouth. The idea was that sailors would use one handicap system to go racing. The Authority of US Sailing was a big factor in CRAC's decision to change to USPN.

The Robustness of the Dixie portsmouth system was limited because it is founded on the premise that fleets of one design class boats are being rated. Catsailors of course are constantly trying out modifications to their one design class. This presents a unique challenge to rating systems that presume a fleet of boats. One offs, or changes in rigs, sail areas, boards, etc etc etc are, by definition, not a fleet of boats. The solution of course was to modify the Dixie portsmouth system that was founded on statistical data collection of class data by creating a table of flat percentage modifications. Presto... the statistical system was now robust!

In 2018, the criteria are the same.. Accuracy, Transparency, Authority and Robustness.

Analysis of the SCHRS 2017 measurement rating table was compared to race results from the French racing scene for these classes.


Summary chart for C1 AHPC Viper Double Nacra 20 carbone F18 A Class classic Nacra 17 old Olympic

The SCHRS annual review states. (I can get permission to forward you a copy if you need)

2.4 All these differences are below 2% and most are as expected. There is nothing here to compel us to make any changes to the formula.
Summary SCHRS is accurate

SCHRS is transparent. Its a measurement rule and ALL of the class OD measurements are published as is the formula used to calculate the ratings. The web site has the data and calculators. Measurement is provided by World Sailing certified individuals.

SCHRS has the authority of World Sailing and US Sailing will be including SCHRS information in the handicap systems that US Sailing supports. (All handicap sailing administration has been moved under the off shore committee.)

SCHRS is Robust. A modification to a one design class is measured and the rating for the specific boat is calculated. A one off design can be measured and a final rating for that boat determined. For the owner.... his rating is by definition "accurate" and independently determined and reproducible since approved measure's use the same techniques. For the fleet, The modified boat is rated using the same methods used for their rating.


Final point, the UK RYA portsmouth system is a statistical system as well but fundamentally different in design then the US system. The UK system rates 10 catamaran classes because those are the active UK fleets that can generate yearly returns. They use a hybrid system for anyone with a boat in the dead boat society.

Will Rottering (Houston Area) is the US representative replacing me going forward. I and another volunteer serve on his US committee.

We would be delighted to answer any questions you have and World Sailing has been extremely responsive in getting final answers to any concerns we have raised.
Mark

Last edited by Mark Schneider; 01/26/18 03:49 AM.

Tiberius worte

Mike Fahle Wrote

HI Mike

Two points SCHRS World committee does an end of the year analysis comparing the gaps in time between the Formula prediction and actual race results. They publish this analysis. For 2017 they report that the gaps or deltas are 2 percent or less for 5 major classes using large events in France for the race data.

Of course a strong one design fleet will see 20 to 40 percent deltas between first and last place finishers sailing identical boats in class... even at the Olympic level! The SCHRS formula is remarkably accurate and no changes to the formula were called for in 2018.

To put this into perspective... consider a theoretical race. with 10 30 footers all sailed equally well. At the weather mark 9 boats will becoming in on starboard and will have to randomly line up bow to stern on the lay line.... The boat on port tack will get to the weather mark exactly the same time as the first boat on Starboard... However, the RRS of sailing will force port to duck the entire parade of boats and round the weather mark in 10th PLACE... On time... they will be 270 feet behind... or around 6 percent behind on time pending their speed over the ground... Even tho they sailed a perfect race. So... what this means is that the RRS will introduce as much as 6 percent error when you try to measure its performance around the race track. SCHRS has developed an accurate measurement formula for beach cats.

Second point, you write
"the sailors seemed to finish pretty much in the same positions regardless of the boats they raced;"

I agree, the pecking order in a fleet is really a good measure of sailing skill and as you noted.... a very good quick check on the validity of any set of calculated race results. We know the top sailors and we salute anyone who sails really well that day and breaks up the ol pecking order...

IMO, what we want is a handicap game that has Accuracy, Transparency, Authority and Robustness. We can go CRAZY about the last significant number in your rating... Forgetting that the RRS introduce noise... We really should value the other three attributes equally.... Having a rating system that is transparent eliminates a lot of the backbiting that undermines a sailors good performance.. Having an Authority outside of the local region also goes a long way in building support for a system. Darline Hobock, was a singular personality who generated national support for her volunteer efforts in administering US Portsmouth for us. SCHRS builds this authority in by its multinational contributors and international support. Of course Robustness ... ie can it handle Mike Fahles custom and home built sail for his mystere 4.3 (I think that was the last sail I remember you working on) is unique to us in the multihull world..... those dinghy sailors tend not to fiddle with their boats in the same way we do....

Take Care
Mark

Now... what happens when Steve Clark's UFO wants to come racing is a new problem... so... hmmm....

Good discussion! My first exposure to SCHRS came with involvement in the Florida 300. I'm impressed with the math and analysis they use to arrive at the ratings.

The biggest roadblock I see to using it widely for local regattas in the USA (besides inertia - "we've always done it this way") is the nature of the bulk of racers at popular regattas (casual and have customized their boat in some way).

The way we do it for the Florida 300 is to use the ratings from the SHCRS ratings table http://www.schrs.com/ratings.php for a boat IF

The skipper can certify that their boat is a factory stock version of the rated boat, otherwise they need to get an individual SCHRS certificate.

If someone shows up to race with a slightly modified boat and no SCHRS certificate then the PRO will assign a rating.

A ha.. the rest of the world calls this process PHRF! (just putting the conventional name to what you do)

Chances are your Race Committee PRO can do a pretty good job of guessing a fair rating.... The sailor can enter the race or not with that rating. The bar could host a lively discussion on ratings or the slimy reputation of XXX or whatever)

How good of a job the PRO does as a ratings expert/ sooth sayer is really not the point....PHRFng the rating is not a good or bad thing...Much of the sailing world in the USA uses PHRF quite happily. its simply just not a transparent or unbiased process.

The advantage that SCHRS provides is that for the NEXT EVENT.... the Owner can go get his gear measured, present the certificate with his transparent rating and play the game with a fully measured boat. Discussion about fair/not fair and bias is simply over. (It doesn't mean everyone is happy with the measured rating... but you know where you stand)

samc99us; wrote

Sam, Good report on West Rivers SCHRS outcomes.....

IMO, This is always a tough ratings problem/choice. A single handed sailor running a rig with two or three sails will have to be really well trained to sail the boat to that rating.... I don't believe SCHRS (or any other system) cuts you a break for your choice of running two or three sails with just two hands.

IMO, You don't want to run three sails single handed on a very crowded and short windward leeward course! On the other hand.... if you know you are doing a Once around a long windward leeward course plus a reach leg out the river.... .... you have a weapon!

Like if a highly modified Tornado would show up at the FL300, they would not be allowed to race with a stock Tornado rating, they would need a different rating. Right?

It depends on the meaning of the word "STOCK" (you are going to hate this answer)

Chances are you define the word "Stock" much like Hobie 16 world.... Basically, if you did not buy it from the factory... its not stock... Oh... and the factory can change things any time they want..... so by definition.... its STOCK.

Maybe, you are a bit more open minded.... you can add a different bugee set up for your trap lines, arguably violating the rule but not the spirit of the rule..... and so it starts.

SCHRS ratings are not going to fuss with how you run your trap lines or what type of running rigging (high tech line) you use. So.... STOCK is a meaningless term for a Hobie 16 rating.

The A class has no concept of stock... They just have a measurement rule box that you must fit in. What is STOCK for an F18? .... do decksweeper rigs count as STOCK? (rhetorical question only)

The T class has had a number of rule sets over the years... The current rule set tried to make it as much like a SMOD one design for ISAF Olympic selection trials after cats were booted. The fleet entered a one design Tornado class in the selection trials..

Would you use the word "STOCK" Tornado to describe the Lovell and Ogletree's Tornado in the China Olympics sporting the only code zero geneker in the fleet going up wind at the start of race 1? By rules at the time.... it was a STOCK Tornado.... QED!.... Of course, what people really meant was.... Was it FAIR.? Bottom line.... ISAF demanded changes in the Rules defining "STOCK" after the Olympics. (The USA Tornado finished dead last... so they shot themselves in their own foot.... so... answer to the ? fair? ... would be Yes it was!@)

My advice would be.... get a judge involved and clearly define the rule set for the race. Make it crystal clear what the standard for measurement compliance will be and put the responsibility on the owners to meet it. NOBODY wins when you half butt this and the OA's lack of rigor opens a door for debate after the fact... That's when you get the BS started that xxx is a cheater boat and everyone just walks away.

so..... maybe you don't want to use the word "Stock" in the rule set!

Fair... is an opinion and likely grounded on where you stand. Not a good word to use in the rule set either.

The other pitfall is using the term "Class legal" without careful thought. Are the numerous Class rules comparable? Is it FAIR for that particular race to run using a Class Rule standard... Hell.... You can't even find a collection of class rules for some classes that might show up..... Why would a fleet of 1 boat in a class need a lot of rules??

Bottom line....think carefully about what you want.

And they were given a new rating, at least for 2017, so I'm not really sure where that issue comes from. It is also up to the race organizers to handle this situation in a fair and equitable manner i.e don't allow entries without valid SCHRS numbers. Assigning on the spot ratings without measuring the boats is questionable at best, but then again this race has always had a cowboy feel...

This is all good advice, but I'm not sure the organizers will take this to heart. If they want the race to continue being successful, and down the road, want the Worrell 1000 to be successful, they need to beef up the rules and actually have an international jury available to take protests. Otherwise you get into all sorts of issues (cough couch Cape Canaveral exclusion zone). The lack of proper management in these areas is a prime reason why I haven't shown up to do the race, among others including wear and tear on a boat that spends a good deal of time buoy racing, plus the usual excuses of time.

Mark I realize your question is rhetorical, but for the rest of the world, the F18 is also a measurement box rule boat...its a much tighter box than the A but things like decksweepers are legal per the rules and at this point are here to stay. Are they faster, well, upwind yes, downwind maybe not. Will the F18 SCHRS rating change as a result? No. Will every one else's SCHRS rating potentially change as a result? Yes, as the benchmark boat is the F18 and if it gets faster then the boats around it have to change, that is simply a result of how the formula works, and it may confuse many sailors.

Then you have classes with ambiguous class rules as mentioned above. SCHRS I think handles that in a good way with a measurement based rule, but it would help if sail areas and mast areas are prescribed by the builders for granting of an initial rating.

Sam, You highlight the rabbit hole in using the term "Class Legal" in a handicap race under ANY rating rule. It is a proven swamp!

Indeed, Deck sweepers are CLASS legal. They are not really an issue in a F18 race... However, once you start down that road... What's class... What's legal.... you wind up explaining F18s as yardsticks, why other ratings may or may not change, and on and on....

Show up for a handicap race against a deck sweeper F18, a "standard" rig and perhaps a Hobie tiger all called F18s. .... Questions will asked about the ratings used. .... God forbid you try to remember ALL of the flavors of the Nacra 6.0 as an OA for an event.... The class names are a trap.... They are a by product of US Dixie Portsmouth.... which is a rating system premised on FLEETS of sailors racing a Class of boat against ANOTHER fleet of sailors in a different class.

Best practice.... don't get into the class ID swamp..... or worse... the class legal briar patch... I think you simply deliver the message... Know your rating.


Most of the events, you don't need to present official paperwork. If you know that you are sailing a OD class legal Hobie 16.... you can honorably look up the H16 rating and report it. .... Its a number.... NOT a report of a class legal Hobie 16.... Likewise the owner of a Hobie 16 with a solid mast... Or a comp tip hobie 16 with non class legal customization.... just report your number... its the owners responsibility to figure it out or get some help. IF you are single handing your class legal Hobie 16...... KNOW your rating... and report it. Its a number! its the owners responsibility!

The "heavily modified Tornado" owner just needs to measure all the modifications etc and report the rating.... ITS a SINGLE NUMBER.... If asked... he can show his certificate that documents that simple Single number.

BTW.... Know your number! Its how all of the PHRF boats go racing... Hell PHRF scratch sheets may not even LIST the boat class.... they want yacht name, Sail number, captain name and your NUMBER....
QED.... Its the owners responsibility to KNow their Number!

ding ding ding. I agree. That's not really why I don't do the Florida distance race anymore but it was definitely a sore spot for me, personally. I don't know that it needs to be an international jury, but at least one trained judge and two knowledgeable/fair stand-ins would probably be sufficient. Adhere to the rules with protests, filings, time limits, impartial adjudicating, etc. Sticking to a very strict regiment of what information should be in an NOR, what should be in Sailing Instructions, and what you can/can't change in the skipper meetings each morning will help everyone have an even and consistent expectation of what they signed up for. That said, it's been several years since I've participated so I'm speaking from an aged, and possibly not current, perspective.

And as far as splitting hairs with a handicap rating, I have two points:
A) these little things like deck sweeper mains and small changes here and there have such a small actual effect on boat performance compared to the mental impact. If you are in the 99th percentile of racing, yes, they may give you an edge - but those guys are hardly worried about their handicap rating.
B) it's handicap racing. By it's very nature it's inaccurate. It's a close swing at leveling the playing field and that's all. If you don't accept it as that, you won't ever enjoy it.

First point... these are two different games we play. Very similar games but you play them slightly differently.



Nope.... to make that argument... you would have to show that Sailor A who routinely just edges out Sailor B in a regatta on one design. Suddenly starts loosing to Sailor B. Your argument would be... the XXX rating system for these two class boats is not accurate. (I have NO examples of this occurring... fact is... the pecking order is about the same in either game)

I think what you want to argue is that handicap racing (and xxx rating system) is NOT AS PRECISE at sorting the pecking order by sailor skill. The analogy would be... two archers shoot bulls eye..... and are tied on points... One archer clustered his shots in a quarter ... while the other one filled the entire bulls eye. You would say... the test of skill could not resolve which of the archers was better that day. Next time... make the bulls eye smaller! (increase the precision needed)

IF you could get valid data... the statistics of signal averaging could get an extremely accurate rating.. of course that is a big if..... AND ignores the fact that you are comparing two slightly different games. My point that sailboat racing rules...(starboard has right away) CAUSE a good bit of the loss of precision in both one design and handicap racing..... So, Focusing on the accuracy of the ratings while ignoring the noise in the game is usually misguided. We actually KNOW how to manage this problem. We play the regatta game.... We spec out a fixed number of races to count . AND a fixed duration... with a fixed number of throwouts. (of course... all of these paramaters are heavily debated in coming up with the best game to sort out sailing skill)

Setting aside the details... here... I would support these statements.
One design racing is a more precise game to sort out sailing skill at an event.
It is VERY Difficult to get enough data to use the statistical power of signal averaging....the ratings are not perfect...
It is also very difficult to write a perfect formula. the ratings are not perfect.

Your conclusion.

Is a very nice bottom line conclusion and I agree with it completely.

That would be correct, if your boat has been modified from stock you need to get a measurement cert. Buoy 44 got their boat measured the first year they did the event on site, the FL300 organizers made the arrangements. Your post reads like Buoy 44 ran a stock Tornado number and that is simply not the case. The stock T number is 0.949, Buoy 44 ran with .924.

Mark, you're right. I currently serve on a local PHRF committee and we have been pushing ORC Club for the serious racers. The "debate" between Portsmouth and SCHRS seems to parallel PHRF vs ORC. Even though Portsmouth is supposed to be derived from observed performance, getting US Sailing to accept the results is quite a challenge. I run a Wednesday Night racing series (20 races during Daylight savings) and we have submitted the results every year for the last 15+ years. There is always a challenge to get acknowledgement. But, it appears that Portsmouth and PHRF (Performance Handicap Racing Formula) are a projected handicap based on a boat's performance; where SCHRS and ORC are more of a scientific measured rating system. I grew up with IOMR, which measures boat specifications and applies a rating based on that. Always seemed straight forward and fair. Now, our larger multihulls use a modified form of PHRF, and they have gotten pretty close to performance; but I am not a fan of a single point rating system. I have raced Nacras, Tornados, and Prindles. In the 90s, we used D-PN and I could tell you who would win based on the wind speed. From my experience, many people who first supported the ORC, quickly changed their tune when their favorable PHRF handicap wasn't a "gift" anymore.

I get it... but users seem to demand a single number system across the board. There does not seem to be much user demand for more elaborate tables.

With a performance based system (PHRF or Portsmouth) the argument for wind speed ratings is stronger. This argument is mitigated by the realization that sailing in breeze on conditions requires more skill and perhaps the performance differences are overstated. Tis a valid debate in the bar!!!

For measurement based systems (ORC or SCHRS) they build in the non linearity correction into the formula. Again, the precision of the game and the skill level bump up in breeze make it difficult to evaluate how well it handles non linearity. Tis a valid debate in the bar!!!

All of the handicap tables are fair minded attempts to make a game of sailing diverse boats possible. YMMV.... again.... a valid debate in the bar!!

Likewise, however, then we wern't experimenting with different sail plans, spinnakers, and other modifications as we are today... at least not until later in the decade. We went to SCHRS this year; however, I don't think the race committee realized that a boats with a modified sail plans needed a measurement...

So my question would be for those that don't have a measurement certificate, how do we level the playing field in an ad-hoc situation.... For instance someone showes up the day of the race with a Prindle 18 with a square top sail, or a NACRA 6.0 with the bridle tangs moved forward to accommodate a larger jib.... do we say OK, that will be a 5%, 10%, etc... hit? Or????

I don't want to be turning people away form a race, but on the other hand I want to see the system work..