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HPR Dual Scoring Analysis, Rolex Big Boat Series
Team McLube


The Publisher

Sep 18, 2012, 12:47 PM

Post #1 of 7 (23880 views)
HPR Dual Scoring Analysis, Rolex Big Boat Series Log-In to Post/Reply

The High Performance Rule (HPR), in development for two years, seeks to meet the needs of rating today's modern high performance monohulls for the highest level of international racing. Dobbs Davis explains the findings from the rule's latest test....

This year’s Rolex Big Boat Series (Sept 6-9) offered dual IRC and HPR scoring for competitors in the IRC C Class, the so-called Fast Forties. The dual-scoring exercise was conducted to examine if this new rating system would be more effective at rating boats that are offshore-capable, yet still be regarded as high-performance: HPR-type boats have high Sail Area to Displacement and Sail Area to Length ratios, and are typically planing off the wind yet also stable enough to have good upwind performance as well. This is in contrast to the heavier, dual-purpose typeform preferred by IRC in this size range.

Entries in Class C included the following boat types – J/125, Farr 400, SC 37, and 1D35 – which were spread over 35 to 41 feet in length, and varied in weight from 2970 kg (6550 lbs) for the 1D35 to 4492 kg (9903 lbs) for the SC 37. There were two windward-leeward races held daily Thursday through Saturday, with the morning race held in a typical breeze building from 10 to 16 knots, and an afternoon race held in a typical breeze at 16-22 knots in strength. Sunday’s single “Bay tour” race was also held in a building breeze, with course content including some reaching. The current was mostly in flood conditions, making windward legs proportionally longer than leeward legs, and for relatively flat water.

HPR ratings were calculated using the latest Version 3C rating calculator, which can be downloaded at There are measurements for select HPR-style designs on a page of this calculator, which have been taken from IRC, ORR and ORCi certificates where available. This rating calculator is a public and transparent means of generating an HPR rating by comparing each of the boat’s measurements to those of a pre-determined typeform design that represents what the HPR deems is the fastest offshore-capable boat of its size.

Ratings are expressed in linear meters, but converted to a single-number ToT handicap, which gets multiplied against Elapsed Time to arrive at Corrected Time.

The attached IRC C graph plots the corrected time difference from the winning boat for each race in both IRC and HPR. While there was no overall change in the winning results - Peter Kreuger and Andy Costello’s J/125 Double Trouble still wins the event – there is considerable compression of the corrected time deltas in HPR compared to IRC. Moreover, Bernard Girod’s Farr 400 Rock & Roll, which was fourth in IRC, takes second using HPR scoring.

This corroborates with on-water observations made during the series: Rock & Roll did better in the morning races with a higher proportion of time spent racing downwind in the residual ebb and/or weak flood tide (Races 1, 3 & 5), whereas the longer and heavier J/125’s did better in the remaining afternoon races with more time spent racing upwind due to the stronger flood.

Even the two smaller boats in the class – the SC 37 Tiburon and 1D35 Alpha Puppy – did better in HPR scoring than in IRC. For all boats the compression rate in corrected time was 20-25%.

A similar study performed on four HPR-style boats in the IRC A class (52-footers Vesper, Meanie and Rio, and the R/P 44 Tai Kuai) shows less dramatic compression in the corrected time deltas than in the 40-footers, and in fact, even some attenuation when using HPR.

On the attached IRC A graph, for example, Race 3 was won in IRC by Manouch Moshayedi’s Rio but not in HPR, and in general fared better in IRC relative to Jim Swartz’s Vesper. But for Thomas Akin’s Meanie, a boat that is heavier and with more sail than Vesper or Rio, HPR scoring gave more favorable results.

Regardless, the accuracy of HPR for the Fast Forties and its non-secret nature for designs of all sizes makes it appealing for those interested in a simple and effective rating system that promotes high-performance design in offshore-capable boats. “Even if IRC and HPR gave similar deltas,” says HPR rule developer Bill Lee, “HPR has the advantage of no assigned hull factors and no assigned rig factors.”

Future events that will offer HPR scoring include: Storm Trysail Club’s IRC East Coast Regatta in Annapolis, October 26-28; Quantum Key West, January 20-25, 2013; Pineapple Cup/Montego Bay Race, February 8-15, 2013; International Rolex Regatta, March 21-24, 2013; Storm Trysail Club’s Block Island Race Week, June 23-28, 2013; LA-Honolulu Transpac, first start July 8, 2013; Rolex Big Boat Series, September 2013.

As more HPR-scored events become available, they will be announced at

Attachments: IRC A.pdf (40.3 KB)
  IRC C.pdf (84.9 KB)

The Publisher

Sep 19, 2012, 11:33 AM

Post #2 of 7 (23618 views)
Re: [The Publisher] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

From Stuart Johnstone:

My personal "two cents" on what happened on SF Bay Big Boat Series as it related to the J/125s and the Farr 400 and other boats-- based on discussions with the actual sailors.

Dobbs Davis commentary on the HPR Rule comparison to IRC Rule stated that the findings "corroborates with on-water observations made during the series: Rock & Roll (the brand new Farr 400) did better in the morning races with a higher proportion of time spent racing downwind in the residual ebb and/or weak flood tide (Races 1, 3 & 5), whereas the longer and heavier J/125's did better in the remaining afternoon races with more time spent racing upwind due to the stronger flood." Huh?

The "facts" seem to be incorrect. Here are the facts about the actual boats taken off the actual websites from both the Farr Design office and J/Boats:

* For starters, the J/125 was designed in the fall of 1997 and built in 1998-- in other words, a 15 year old design. It is 12.5m long on deck. And, it weighs about 3,800 kg.
For fact check-

* The Farr 400 was designed around 2010 and built in 2011. It's 11.8m long on deck. And, its designed weight is about 3,900 kg.
For fact check-

* The basic differences between the J/125 and the Farr 400 are the following:
- the Farr 400 has higher freeboards (therefore more windage) and much fatter bow sections with a blunter bow (only effective in super-flat water and seemingly not in chop or waves upwind or downwind).
- The rig dimensions are remarkably different, with the Farr 400 having a much taller rig with an ISP at 58.5 ft!
- The J/125 has an Upwind SA of 1,071 sq.ft and Downwind SA of 2,464 sq.ft. The Farr 400 has an Upwind SA of 1,098 sq.ft and Downwind SA of 2,530 sq.ft.
- The DSPL differences are largely driven by the differences in the bulb/keel weights and keel depth.
== Farr 400- keel- 4,796 lbs/ 2,180 kg- 9.5 ft/ 2.9m in depth
== J/125- keel- 4,646 lbs/ 2,107 kg- 7.9 ft/ 2.3m down
-in terms of "length", the Farr 400 is actually LONGER on the loaded (effective sailing length) waterline than the J/125. Go figure. The J/125 has a "raked" bow vs the Farr 400s plumb bow and transom- so the J/125 is "giving up" about 10"-18" of effective sailing length on the waterline.
- the boats are about the same weight given the differences in owner spec's for what stuff is loaded onto them.
- plus, the Farr 400 is supposedly benefitting from millions of dollars of tank-testing/ VPP work on Volvo 70s, America's Cup stuff and Offshore 60s, etc-- in other words, the latest thinking in offshore/ around-the-buoys design, equipment and materials.

So, take that one back to your collective drawing boards and "performance calculators"! In other words, using ALL the collective wisdom of SA/DSPL, SA/WS, RM, SA/WL and other "horsepower" factors, on paper the Farr 400 should've killed the J/125. Sadly, that was not the case. As everyone who's observed the "facts" on San Francisco Bay for the past two years--- the J/125s simply eviscerated the Farr 400-- the latest and greatest the world had to offer in "sportsboat" keel design. Like the latest Botin-Carkeek 40, the Farr 400 can go downwind fairly well, but like any other "wedges of cheese", they simply cannot go upwind-- it's very, very hard to sail tipped-over upwind with the fat rear-end of a boat pushing the bow underwater all day long (simple physics would tell you that). Ever wonder why modern TP52s in their 7th generation or so of design have evolved back to "moderate planforms" or why I-14s and Aussie 18s actually have some rocker and curvature in their diagonals in the "rear-ends"? Yes, even they have to go upwind sometimes without nosing under and "sending it down the mine"--- upwind.

What does this mean for the HPR Rule designed to create an "equal play-ground" for the latest "sportboat/ high-performance" designs? Perhaps they'll have to re-think some of the parameters. After all, isn't it a bit of a regression to consider the fact the latest "HPR" design is getting beaten badly (boat-for-boat, no less) by a 15 year old design that was built to sail fast and have fun with a family crew?? Case in point-- J/105s sailed by complete amateur crews are about as fast as professionally-crewed Melges 32s going upwind in 18-23 kts on San Francisco Bay-- proven dozens of times. Can the HPR equate that potential issue?

If you want to consider the latest generation sailboat designed to be fun with little cost and no drama in the "fast forties" range of 35-40 foot sailboats, then forget HPR. You should sail a J/111 speedster--- already proving it's capabilities to eclipse fleets around the world in offshore handicap racing sailed by families and friends. Plus, one-design fleets are already formed in the Great Lakes, New England/Northeast, the United Kingdom and France!


Sep 19, 2012, 2:43 PM

Post #3 of 7 (23584 views)
Re: [The Publisher] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

It’s too bad the Stu J has taken this neutral analysis and turned it into a product review and an opportunity to give such a blatant promotion for J/Boats. It was not the intent of this analysis to generate this kind of debate, but merely show that HPR ratings may have worked better than IRC ratings for these boat types.

Indeed, it’s puzzling why he expresses such a strong indictment against HPR when a well-honed team racing on his own product has just shown outstanding results using this system!

Regardless, there are a few facts that may be at odds with Stu’s ‘facts’:

- the weight data quoted in the analysis was not from manufacturer’s claims in marketing literature, but from actual measurements taken from ORR, IRC and/or ORCi certificate data - this is shown in the ‘Database’ tab of the HPR Rule Calculator spreadsheet. The two J/125’s in the database have empty weights of 4303 kg and 4369 kg, and the F400 a weight of 3950 kg. We can let the readers decide why there is a difference in the claimed weights versus the actual weights.

- Since IRC rules were used at the Big Boat Series, crew weights were not measured, and therefore only default weights were used in the HPR ratings. For the Farr 400 this was assumed to be 703 kg, and for the J/125 760 kg. If the actual crew weight were more, then of course this would benefit the boat’s upwind performance.

- The Farr 400, like the J/125, is a design that pre-dates the development of HPR, and therefore cannot be considered as “the latest HPR design.” And the latest design trends in wide stern sections are not prompted by HPR, they merely reflect some designer’s ideas on how to best position crew weight to benefit upwind and offwind stability.

- Claims cannot be made about the performance of the “Botin-Carkeek 40” (which is actually a Carkeek 40 - Shaun has not been partners with Botin for almost two years) since it was not entered in the event and thus not part of this analysis. But for readers’ interests, it is a fact that the latest boat of this design – Steve and Heidi Benjamin’s Spookie – last weekend won the Long Island Sound IRC Championship, defeating several different boat types in a variety of conditions on windward-leeward courses. By all accounts the boat went upwind just fine, as did Decision in the close-reaching conditions of the Newport-Bermuda race.

The intent of HPR is to use actual measurements to openly rate any fast, stable, offshore-capable boat without reverting to secret hull and rig factors or PHRF-style assumptions on performance. So perhaps, like the J/125, the latest J/boat product in this genre may do well, and it will be up to Stu’s J/111 customers to come try this out if they are unable to race one-design and are interested in an alternative to PHRF or IRC.


Sep 20, 2012, 6:48 AM

Post #4 of 7 (23509 views)
Re: [dobbsdavis] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

Hi Dobbs

I confess I was also mildly disappointed at Stu's response, if only because I'm desperate for informed professional analysis of this new rule. But I don't think Stu's response was any more a "blatant promotion" than many of the comments by HPR people like Bill Lee and your good self about how great HPR is :-)

I've no issue with somebody defending their yacht/project, but it didn't add much to the story. Mind you, at least it's a response - how depressing would it be if Team HPR went to all this trouble to make up a new rule and nobody cared!

I read your analysis with interest, and trawled as much info as I could throughout the BBS (and at Key West etc) but all I could conclude was how difficult it is to try to make something out of such a limited data set in a sport as complex as sailing. In a similar example, you could analyze the IRC results at RORC Commodore's Cup this summer and come up with totally random results - out of 21 fairly classic typeformed IRC boats, the new "light" Ker 40s finished up overall something like 1st, 6th, 10th, and 19th - so you could make up any story you wanted as to how IRC rates the new designs. I would imagine that the Big Boat Series story is similar.

I would find it much more helpful if you could provide a simple comparison in terms of seconds/hr between the correct ratings (proper sail areas, inclinings, etc) of the boats under HPR and IRC or ORC. That's what I really want to see. Because I'm struggling to see how HPR is going to create a critical mass of players if it doesn't attract boats/owners out of other rating systems, and in order for an owner like me to make that jump I'm going to want to know how I rate against other boats under HPR as opposed to under IRC or ORC. Sorry if that doesn't seem very noble...
I'd also like to know if HPR has any plans for a regatta outside the USA.

Our Ker 40 gets back to HK this coming Tuesday and along with Ambush the Mills 41 we're going to try to get our heads around the ORC and HPR measurement process (we're basically IRC guys as you know)so that we can compare our boats, like we've done under ORCclub and IRC. We'd love to see more commentary from other owners involved in HPR, especially if they have IRC background data. And of course every incremental result and every different boat that tries HPR adds to the general analysis picture.

Jamie McWilliam in HK


Sep 22, 2012, 2:15 PM

Post #5 of 7 (23417 views)
Re: [wanchaibelle] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

Hi Jamie –

Always great to hear from you, and for those following, Jamie is a great student (and practitioner) of rating rule system use. He and his colleagues at Royal Hong Kong YC did an exhaustive study two years ago on their local fleet to try and help determine the best system for their local use, and I think are still studying this issue.

It is of course hard to draw conclusions from limited data sets, but at least at this Big Boat Series a few variables were reasonably controlled: 1) race management was excellent; 2) teams were generally at a high level, this being an important event; 3) breeze conditions within the class examined were uniform; 4) the course area was not quite as crowded as in year’s past, making for multiple tactical variables in the results.

And to answer your question about sec/hr comparisons between systems, this could be derived from the corrected time analysis on the plotted graphs: the deltas in corrected time between boats scored using HPR is less than IRC because their differences in TCC are less.

I did not look at ORC in this study, simply because ORC scoring was not an option at this event, but it would be a simple matter to do this, and I can certainly contact you offline and share the data I have.

HPR is gaining traction here for some rather simple reasons: a general feeling that the boats that rate well in IRC in this size range are not fast enough to interest the high-performance crowd that have light, fast boats, and a general dissatisfaction with the non-public hull and rig factors when HPR can be described on a spreadsheet.

I’ll look forward to our continued dialogue on this topic Jamie!

The Publisher

Sep 25, 2012, 11:41 AM

Post #6 of 7 (23301 views)
Re: [dobbsdavis] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

From John Clauser and Bobbi Tosse

NorCal PHRF ratings provide better handicapping for the 2012 Rolex Big Boat Series than do either HPR or IRC ratings.

Recently, discontent with the IRC rating rule has spawned the HPR rating rule. Dual scoring under both HPR and IRC of a very small subset of the 2012 Rolex Big Boat Series (Div C, with only four boat types) was offered as a possible test of the new rule. The results were reported recently in Scuttlebutt by Dobbs Davis. He noted a “dramatic compression (20 – 25%) of the corrected time deltas in HPR compared to IRC”. He also reports a “less dramatic compression of the corrected time deltas” for “four HPR-style boats in the IRC A class”.

It should be noted that the NorCal PHRF system was used prior to 2000 for handicapping the StFYC Big Boat Series. It was therein rebranded as the StFYC Handicap System (to allow minor adjustments to it by StFYC). Following a squabble between US Sailing and RORC over IRC, IRM and IMS usage for international events and the Admiral’s Cup, the StFYC Handicap System was replaced by IRC for BBS handicapping, and has been used thereafter.

Sadly, the popularity of IRC on the Bay has significantly and continuously declined since then, as has the number of BBS handicap entries. Moreover, the StFYC is the only club on San Francisco Bay to offer IRC handicapped regattas. In 2012, it offered 3 IRC events -- the Rolex BBS drew 24 IRC boats, the Phyllis Kleinman Swiftsure Regatta drew 8 IRC boats, and the Aldo Allesio Regatta drew only 3 IRC entries whereupon its IRC class was canceled for lack of interest.

On the other hand, PHRF events thrive on the Bay. For example, the 2011-2012 Corinthian YC’s 4-race mid-winter series drew at least 35 BBS-qualified entries. The authors’ limited survey of the owners of a few boats who eschewed entering the 2012 BBS revealed that they felt that IRC gave them grossly unfair handicaps, whereupon they believed that entering was pointless.

With the declining popularity of IRC in mind (with respect to NorCal PHRF), it is perhaps worthwhile to consider what the results of the 2012 Rolex BBS would have been, had it been instead scored using NorCal PHRF (i.e. the old StFYC Handicap System), and to compare the corrected time deltas for IRC, PHRF and HPR. As with Dobbs Davis’s study, we shall use the statistical spread of corrected time deltas as a “figure of merit” for the quality of the handicap system – a narrow spread indicates a fair system, while a wide spread indicates an unfair system.

It is thus the purpose of this note to present the results of this comparison. For improved generality and statistical accuracy, we include all IRC BBS entrants in this study, and not just the very small number of HPR boats considered by Dobbs Davis

Table 1 (BBS_IRC_spreads.pdf) shows the IRC-handicapped results for each boat in each of the seven races of the series. To account for the fact that different divisions sailed different courses in each race, and to allow a cross comparison of the different divisions, each race result presented in the Table is the associated boat’s corrected time divided by the associated race length. Then, for each race and each division, the associated unbiased standard deviation is calculated as a measure of that division’s spread of corrected time deltas for that race. Finally, (in the last column) for each division, the average standard deviation is calculated as a measure of the division’s spread of corrected time deltas for the seven race series.

Table 2 (BBS_PHRF_ spreads.pdf) shows the same results obtained using the NorCal PHRF ratings. Notes to the table indicate assumptions, adjustments, and/or corrections regarding the PHRF ratings therein used.

Table 3 (BBS_HPR_ spreads.pdf) shows the same results obtained using HPR ratings, i.e. Dobbs Davis’s calculation here allowing for a variation of race lengths, as discussed above.

Several conclusions may be drawn from a casual perusal of the results presented in these tables.
  1. A comparison of the HPR results of Table 3 with the Div. C results of Tables 1 and 2 shows that the compression of corrected time deltas in HPR compared to IRC (as noted by Dobbs Davis) is almost exactly the same as that observed under PHRF handicapping compared to IRC. That is, HPR and PHRF give equivalently improved results for Div. C (about a 20% reduction of the spread).
  2. For Div. A as a whole, PHRF provides a whopping 51% reduction of the corrected time spreads, relative to IRC. (Note that Dobbs Davis reports a “less dramatic reduction” of the corrected time delta for his Div. A 4-boat subset than that which he observed for Div C. (15-20%).
  3. For Div. D, PHRF provides a 5% reduction of the corrected time spreads, relative to IRC. Curiously, for Div. B, PHRF provides a 20% increase of the corrected time spread. However, Div. B is the smallest of the four divisions (only 5 boats), whereupon its results are presumably less statistically significant. On average, for all four divisions, PHRF provides about a 14% decrease in the corrected time spreads, whereupon it may be judged as the fairest among the three rating systems considered.
  4. Neither HPR nor PHRF provided different division winners with respect to IRC. However, under PHRF, Vesper’s Div. A win is now decided via a tiebreaker with Swiftsure. As might be expected, both HPR and PHRF, however, do shuffle some of the subsequent positions relative to those of IRC.

All three rating systems (IRC, PHRF and HPR) offer a single number rating. Another noted advantage touted for HPR over IRC is that HPR is a measurement rule, while IRC involves subjective judgments in the assignment of its ratings. A noted disadvantage (to many) of HPR is that it is self-admittedly strongly type forming. If a single-number-rating measurement rule that is not type-forming is deemed appropriate, perhaps ORR-16 knots WL might be considered as appropriate for typical BBS conditions. Note also that Transpac and Pacific Cup have both spawned a significant number of available ORR certificates for west coast boats in the BBS size range.

A noted advantage of HPR over IRC is that HPR is not a secret rule, as is IRC. IRC’s total lack of transparency fosters a mistrust of the rule’s uniform application. To be sure, one may purchase IRC secrets at about $120 per secret for a 40’ boat, but no purchase of a boat’s base rating decision criterion is offered. By contrast, both ORR and NorCal PHRF are far more transparent in their assignment of ratings. Last year’s IMS/ORR VPP is available for purchase, so that its whole rating process is available for scrutiny. Also, to the credit of the NorCal PHRF committee, its meeting minutes are open for perusal on-line.

In summary, it appears that NorCal PHRF provides improved handicapping for Rolex Big Boat Series events. PHRF appears to be every bit as good as HPR, but has the advantage that it can be applied to the whole fleet, rather than to a very limited subset of the fleet. It is also far more popular locally, and undoubtedly offers increased attendance of handicap boats in the event. Alternatively, if a single-number-rating measurement rule is deemed appropriate, perhaps ORR-16 knots WL might be considered as appropriate for typical BBS conditions.

John Clauser and Bobbi Tosse, 2012 Rolex BBS participants

Attachments: Table 1 BBS_IRC_spreads.pdf (200 KB)
  Table 2 BBS_PHRF_spreads.pdf (203 KB)
  Table 3 BBS_HPR_spreads.pdf (181 KB)


Oct 9, 2012, 12:16 PM

Post #7 of 7 (20892 views)
Re: [The Publisher] HPR Dual Scoring Analysis, Rolex Big Boat Series [In reply to] Log-In to Post/Reply

This is a reply to the last post on PHRF from HPR Rule author Bill Lee:

John Clauser and Bobbi Tosse did a great job of discussing the use of handicap systems on San Francisco Bay. Unfortunately with rating systems, one size does not fit all. Before getting into individual systems, I should mention that a couple of years ago, Mike Urwin from RORC suggested the possibility of a Universal Measurement Form. Once a boat measured under that form, the rating could be calculated under any participating rule and with no additional measurements. US Sailing and RORC have developed an initial version of the UMF which does include PHRF dimensions along with those of the measurement rules, ORR, IRC, and IMS, which is the measurement system behind ORCi, ORCclub, and the ORC GP rules. The concept of the UMF will increase the ease of cross over between rules, which will make it easier to use the right rule for the right job.

As to the right rule for the right job, PHRF does a great job and with 25,000 active boats, it is the largest rating system in the world. It works best in local areas where the local handicappers know both the boats and the conditions they will sail in. StFYC did successfully use it in 2000, but because boats may travel from different localities, each with it's own local PHRF board, the ratings had to be synchronized which is an opportunity for either error or the perception of favoritism.

But the biggest issue for a high level regatta like BB is that owners often optimize the boats for the event. They buy new sails which may not match their previous PH certificate, change ballast, etc. In the absence of measured data for each boat, there is no way to know whether two supposed sister ships are in fact identical. Some years ago Transpac advanced from "PHRF data" to "PHRF data with measured sails." Some ratings came in up to 5 seconds per mile faster. Now Transpac requires fully measured boats under ORR. Also, PH only recognizes steps of 3 seconds per mile which is insufficient for slightly modified or highly tuned boats. US Sailing can back up a StFYC PH effort, but without measured data, there is only so much they can do. All of the reasons PHRF works so well for local events unfortunately work against it for high level events involving boats from multiple areas.

BB does not have to use the same rule for each division. For the planing boats, HPR is the right rule, first because it is designed for planing boats, and second because other rules, including PH have difficulty handling planing boats, especially new boats with no history.

I believe discussions are underway on the best rating system for each division in the 2013 big boat. The UMF should be a big help in increasing versatility select the right rating system and getting the boats measured in.

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