New Base/Changes to Base Rating Procedure

Race Results and Observed Boat Speed

Other PHRF ratings

IMS and other rating comparison

Technical Comparisons


To establish a new base rating, to review possible changes to a base rating, and to resolve any appeals of a base rating, the committee will proceed in accordance with the by-laws and as follows:

The committee will attempt to obtain and consider the following data and information:

  1. Race results and boat speed observations,
  2. Ratings from Other PHRF areas,
  3. IMS, IOR, and any other ratings and comparisons, and
  4. Technical comparisons to other boats

The order of importance/weight given to each of the above is generally in accordance with the above listing, however, the significance or quality of the data for each of the categories listed above may vary greatly. For example, a new boat may have no race results and no ratings from other areas; therefore, the committee may only have an IMS rating and Technical comparisons to help determine a rating. Lastly, the committee will use its best judgment in arriving at a decision based on all the data, which is often, by itself, inconsistent


Race Results and Observed Boat Speed:

The more the better!!! More than one boat/skipper, more than one regatta, corrected/elapsed times in addition to places, are all desired. The seriousness of the regatta/competition, the effect on results if the rating was changed, comments of side by side speed comparison to boats with known good ratings will all be considered. Data for one boat, one race will not carry much weight, while conversely, data from multiple boats and regattas will greatly affect the committee’s decision.


Other PHRF ratings:

Ratings from surrounding areas, i.e. NE, WLIS, and ECT, other areas, and overall average rating will be reviewed. Areas that claim to have a firm basis, with multiple boats, will be given more weight than other areas. In general, NB is 3 sec/mile more lenient than others. In addition, comparison of ratings to other boats of similar size/rating shall be reviewed.


IMS and other rating comparison:

The committee shall maintain a suggested factor to convert IMS to PHRF.The number of boats, genoa size, displacement, crew adjustments, spinnaker pole and propulsion penalties and IMS rating comparisons to similar boats all need to be considered. The average needs to be suitably adjusted based on experience with similar boats .For 2002, IMS – 545 = average PHRF. However, IMS exhibits inconsistency with known good PHRF ratings of +12 to –12 sec/mile for normal boats, and up to 20 sec/mile inconsistency with non standard boats. IMS ratings for boats less than approximately 35 feet have proven not to be very accurate. IOR and other ratings can be reviewed, but in general, are not very accurate.


Technical Comparisons:

Technical comparisons to similar size and type boats with existing PHRF ratings shall be made. The committee shall maintain suggested sec/mile adjustments for sail area, displacement, LWL, draft, and other design differences. Comparisons to extremely similar boats shall carry much weight, while conversely comparisons to dissimilar boats shall not be considered to be accurate.



Where possible, the committee shall review and consider all of the above data to establish a new base rating, or when reviewing an existing rating under appeal or consideration for change. Ideally, a rating will be consistent/supported by race results and observed speed data, and will be within +/- 6 sec/mile of the ratings from other PHRF areas, IMS ratings, and technical comparisons to similar boats. When the data is not available or is inconsistent as is typically the situation, the committee shall use its best judgments on the data to arrive at a new or revised rating.


2000 IMS Analysis

The 2000 IMS is approximately 5 sec/mile harsher that 1997 IMS (the last time this analysis was performed. However, the inconsistencies between IMS and PHRF seems to be much greater in 2000, and bizarre in some cases. The average adjustment to convert IMS to PHRF-NB is

IMS2000 - 537 = PHRF,

with inconsistencies of +15 to – 15 for “normal, non-IMS” boats.

Some comments on how IMS treats different classes/designs, vs PHRF (truth), area as follows:


Center Boards 20 harsh  
Cals 15 lenient
Catalinas 15 harsh
Blackwatch 28 lenient
Eriksons very inconsistent +7 to – 20
Older Frers 10 lenient
96 Farrs 8 lenient
J24, 29MH, 35, 44 15 lenient
Other Js OK
96 N/Ms 12 lenient
Pearsons 15 harsh
S2s 15 lenient
Sabres 10 harsh
Swans inconsistent +13 to –15
New IMS designs 25 lenient


The New Base/Changes to Base Rating Procedure describes what data the committee reviews and considers when reviewing appeals and or changes to Base ratings. The more information that the committee receives, the better the decision. In general, the appellant should provide race results, times, and the effect of any requested changes on the race results. For example:

"My results for the season was 10, 11, 6, 2, 8, 1, 9, and 8, with an overall of 7 out of 10

With a 6 sec/mile change, my results would have been 7, 10, 2, 1, 5, 1, 8 and 6 with an overall of 4 out of 10."

Race results for all skippers of that boat are especially useful.

Comments on boat speed comparison are appropriate and should be provided:

"I’m slightly slower than a J29 upwind, but much faster downwind. I think that overall I’m about 3 sec/mi faster than a J29"

Any confusion as to the configuration of the boat (e.g. Tall Mast Version), or any design peculiarities should be clarified.

Other PHRF ratings, IMS ratings, and Technical comparisons can be provided and are useful, but, in general, the committee may already have access to this information.

Data and information should be provided in a factual manner. All data. both favorable and unfavorable to your position should be provided. "Biasing or withholding information" will not impress the committee. Personally appearing before the committee is sometimes helpful, but not necessary. Assume that the committee is trying to be as honest and fair as possible, are experts in handicapping boats, but may not know the details and have the necessary data and information on your particular boat and the circumstances surrounding it.

Please send all material to the PHRF office as soon as possible. If you appear in person, you may bring additional people, if you desire (not necessary). You will be asked to present your opinion, comments, and recommendations; answer questions and discuss various issues. Final deliberations by the committee will be done in private. Although the rating chairman will typically lead the discussions, all committee members have an equal vote on the decision. You may find that a committee member is a competitor of yours. This is a natural consequence of PHRF being an observed performance handicap system and is allowed by our by-laws. If you feel that that member is unusually biased, please note your feelings to the committee.

Remember: the goal of the committee is to promote and encourage racing by having PHRF ratings that are fair to both you and your competitors.



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