Classic Rating Formula
The goal of the Classic Rating Formula (CRF) is to provide an objective, accurate and transparent rating system that is uniquely suited to scoring classic yacht races. CYOA's CRF Technical Committee routinely refines the formulae and factors used to calculate ratings annually, based on careful quantitative analysis of race results after each season. Maintaining the competitive balance within groups is a priority, but the ratings for most yachts will often change slightly from one year to the next even if the declared input data remains the same.
Each year, each vessel needs a new CRF Certificate ($50 per certificate with a $25 rush charge after June 1). Certificates only cover a portion of our operating costs and we rely heavily on volunteers. We encourage owners to also support the CYOA's efforts with a $100 membership each year.
2021 CRF Rating Documents
December 9, 2020
As CRF has been refined since, experience has exposed the need for some additional data declarations beyond those required for its earlier incarnation.
December 9, 2020
A review of the 2020 season with a focus on how well CRF ratings matched up with real world race results By Jim Taylor, CYOA Technical Committee
July 30, 2020
When CRF was fundamentally revamped in 2017 and re-introduced as ‘ CRF MkII’, the new formulae, factors and resulting ratings were vetted by a careful analysis of years of Classic race results.
Keel Types and Descriptions
Rig Types and Descriptions
Frequently Asked Questions
A. In most years, the data declarations made for one year will be the same as those for the next year, and that data will auto-load with your renewal application.
A. The CRF formulae and factors are routinely refined annually to reflect biases that were identified via an objective, in-depth analysis of the previous year’s race results. Typically most ratings change only slightly, and those that see a significant change will find that other yachts of the same size and type will have changed by a similar amount. Maintaining the competitive balance within groups having similar characteristics is always a primary objective.
A. The divisions assigned by the CYOA Technical Committee are provided as guidelines to Organizing Authorities; each regatta may, based on their individual traditions or numbers of entries, place competitors in different divisions, so you may not compete against the same yachts in the same class in all events.
A. The formulae and factors used to calculate ratings are routinely refined annually, based on a quantitative analysis of race results from the previous season. As a result of these refinements, ratings often change from one year to the next even when the same input data is declared.
A. The online application/revalidation process for acquiring a CRF certificate is quite straightforward, with pop-up help available for data definitions. Most of the information required is the same from year to year, and it is resident on the site under your online CRF account. You should check all of your declarations to be sure that they accurately reflect the way that you intend to race your boat this year, but you will not have to re-enter them if they have not changed. Occasionally some new data will be required that has not been included in previous years.
Beginning with CRF 2020, the following additional information was be required:
– Standing rigging material, if not provided previously. This was requested in 2019 but not used in calculating ratings. It was be required in 2020, and is used in calculating ratings beginning in 2020.
– Stern type for canoe sterns (double enders) only.
– Mainsail and spinnaker girths (luff to leech widths). This data was gathered for rule development testing beginning in 2020, and will likely be used in calculating ratings in 2022.
– Design and build year (to help with division assignment)
A. Certificates of all currently registered classic yachts may be viewed by going to the CERTIFICATES CRF Database.
A . A first step should be to check the declared data on which the rating is based. CRF is committed to full transparency, and all valid CRF certificates are available for inspection online. If you still have questions, you can file a rating inquiry.
On receipt of your inquiry, the CRF Technical Committee will review the certificate, and if they determine that there is a error, they will notify the yacht owner of the error and of any resulting change in rating. If the measurement in question needs verification from an independent outside source, a measurer will be hired at the expense of the appealing party.
A. First, while it is possible that an input error has been made, be aware that the formulae and factors used to calculate ratings are routinely refined each year, so ratings often change from one year to the next. For example, beginning in 2020, a Standing Rigging factor effected ratings compared to 2019, as did an improved Stability Correction. Similarly, beginning in 2020 ratings reflect an adjustment to the effective sailing length of canoe stern (double ended) hulls.
Of course, it is possible that an error in data input has been made. If you feel that this is the case, file an inquiry. On receipt of your inquiry, the CRF Technical Committee will review the data to see if there is an error. If so they will notify you, correct the rating, and issue you a new certificate.
A. File an inquiry and see our process here. Your request will be reviewed by CRF, and if there is an error, they will notify you, make the change in the data, and issue you a new certificate with the corrected measurements.
A. No. A boat can have just one valid certificate and one pair of ratings at any one time. A boat will be allowed one configuration change (e.g from a big genoa to a small jib) during any one racing season. A new CRF certificate reflecting that one change must be issued at least 10 days before the next race in which the boat competes, and the boat may not revert back to her original configuration later in the same season. This ‘one change’ limitation does not preclude correcting errors or making minor updates to declarations, which may be accepted and a new certificate issued, at the discretion of CRF administration.
A. A CRF certificate is valid for the calendar year in which it is issued, and must be renewed each year in order to be valid for racing.
A. Once processed, your will receive a link to your certificate. You may send that link to regatta organizers so they have a copy of your certificate.
A. Although the application is processed automatically for a rating, to ensure accuracy each certificate will be manually reviewed before it is issued. CRF typically starts issuing new certificates in April. After that start up, plan on at least 5-7 business days early in the season. If applying during July and August, it may take longer due to a larger number of certificates being issued.
A. A certificate costs $50.00. The fee contributes to the expenses of rating rule administration and development.
A. Designer data, builder specifications and brochures, etc. are typically the best source. If necessary, the CRF Technical Committee can help with researching ballast data or even calculating it from measurements.
To request help in calculating your ballast weight, complete as much of your CRF Application as you can, use our Data Inquiry Form to request help and specifically request assistance in determining your ballast weight.
A. Check the box corresponding to the underbody profile that most closely resembles the fixed portion of your keel and your rudder type. CRF accounts for the effect of the centerboard via the declared value for ‘Draft Centerboard Down’.
A. Stability and wetted area are critically important performance parameters, but it is not reasonable or practical to ask yacht owners to declare appropriate values for them. The 6 underbody types displayed on the CRF rating application work indirectly as surrogates for stability (via related keel volume, VCB and VCG), and more directly for wetted area. In addition, the various underbody type options help account for the advantages of a high aspect ratio fin keel with a separated spade rudder over a lower aspect ratio configurations, including a full keel with an attached rudder.
A. If you are declaring a displacement that is heavier than the designer/builder specification, it follows that your declaration for the LWL that corresponds to that heavier displacement should be longer, and that your declaration for Draft should be deeper, than the designer/builder specified values. One way to quantify the differences in LWL and Draft (DM) would be to estimate the sinkage resulting from the difference between the designer/builder spec and the declared displacement (DSPS). The ‘Pounds per Inch Immersion’ (sink) for most boats can be approximated by: Lbs/in Immer = 1.1*LWL^2. It follows that actual sinkage (in inches) = delta DSPS/Lbs per In Immer. This estimated sinkage would equal to the amount added to the designer/builder specified Draft (DM) in inches , and for most boats multiplying this sinkage by 6 approximates the amount added to the designer/builder specified LWL, also in inches.
For example: Suppose that the designer/builder spec for the displacement of a boat is 40,000 lbs, but the actual displacement has been determined to be 46,000 lbs. If the published value for LWL = 38.0 at the lighter floatation, an estimate for ‘pounds per inch immersion’ would be 1.1 * LWL^2, or 1588 lbs. This implies that the boat would float deeper than the original spec by (46,000 – 40,000) / 1588 = 3.8 inches, or 3.8 / 12 = 0.31 ft. This, in turn, would imply that the actual LWL would be 38.0 +6 * 0.31 = 39.9 ft. Similarly, if the published draft were 5.33 ft, the implied actual draft would be 5.33 + 0.31 = 5.61 ft.
A. Designers and builders typically provide displacement data referenced to the ‘design waterline’ that most often resembles a ‘light ship’ condition, with empty tanks and minimal food and gear. The weight added in equipping and provisioning for coastal cruising can increase that displacement by 10% or more. The boat hauling equipment in some yards can provide a boat weight, but these weights are typically not especially accurate, and should be used as a rough reality check only. If a displacement is declared that is significantly heavier than the original designer/builder spec, the declarations for LWL and draft (DM) need be longer and deeper, respectively, by appropriate amounts.
A. A spinnaker is any sail set forward of the foremost mast whose width, measured between the midpoints of its luff and leech, is equal to or greater than 75% of its foot length. A headsail is a sail set forward of the foremost mast whose width, measured between the midpoint of its luff and leech, is equal to or less than 75% of its foot length. (See RRS 55.4 and Equipment Rules of Sailing G.1.3 d&f).
A. Requests for sail girths (widths) for mainsails and spinnakers were new for 2020. They were intended then to be for newly built sails only, as the data for those would be readily available to owners from the sailmaker. These sail girths were used for data gathering only and not for ratings in 2020. The intent is to include mainsail girths in ‘CRF 2022’ sail area calculations for newly built sails to reflect the fact that modern sailmaking methods and materials can support mainsail roach profiles that are substantially more aggressive than those that are typical of the existing Classic fleet, and this has given those new sails extra area that has been ‘free’ in terms of rating. Similarly, in the interest of simplicity, CRF has been calculating a downwind sail area that includes an assumed spinnaker area that is a function of the height of the chute halyard and the length of the pole and/or spinnaker tack point. To head off teams gaining an unrated advantage by building spinnakers with girths that are larger than those that are typical of the Classic fleet, for ‘CRF 2022’ the area for newly built spinnakers will likely include their measured, rather than an assumed, mid width.
A. Sail material guidelines are intended to encourage the use of sails that are cost efficient and that are aesthetically appropriate for Classic racing. Classic Yacht Racing Guidelines first published in 2020 remove the prior requirement for paneled construction and allow for ‘molded’ sails. This change also removes the requirement for ‘woven fabric.’ In the Vintage and Classic divisions, carbon is prohibited (since low stretch sails risk damaging older hulls hardware, and rigs), and only classic, light colored sails are allowed. In the Spirit of Tradition and Modern Classic Divisions, sail materials and colors not restricted.
A. The rigs of some older boats have been upgraded by replacing the original wire standing rigging with stainless steel rod, which implies a rating advantage. Also, some boats are fitted with composite (typically carbon) standing rigging, that results in a substantial performance advantage. A Standing Rigging Factor that was new for CRF 2020 addresses this advantage via a rating adjustment.
A. Yes, as long as you declare a spinnaker pole length ‘SPL’. Note that a whisker pole can only be used to wing out a headsail, and not to trim a spinnaker. Also, be aware that if you do declare an ‘SPL’, your calculated spinnaker area will be larger, and your rating will be faster, than it would be if you declare just a centerline a-sail tack point ‘TPS’ with a length equal to that ‘SPL’. This higher rating is due to the fact that being able to square back a spinnaker pole increases projected spinnaker area and in some conditions it allows a boat to sail at deeper true wind angles off the wind, resulting in potentially higher downwind VMG.
A. Yes, as long as you declare a spinnaker pole length ‘SPL’. If you declare both a pole length ‘SPL’ and a spinnaker tack point ‘TPS’, CRF will calculate a spinnaker area for both an s-sail via SPL, and an a-sail via TPS, and it will calculate rating on whichever area is larger.
A. Any pole used in trimming a spinnaker is a spinnaker pole, and it is rated as such with its overall length declared as ‘SPL’. A whisker pole is a pole used to wing out headsails only, and its length is limited to not more than 1.1 * ’J’. A spinnaker pole with a declared length not longer than 1.1 * ’J’ can be used as a whisker pole to trim headsails. A boat can use a spinnaker pole with either symmetrical or asymmetrical spinnakers, but if a spinnaker pole is declared, the boat will be rated for an s-sail spinnaker area, whether or not she actually carries any s-sails.
A. ‘TPS’ is the distance from the forward face of the mast to the attachment point for an a-sail tack to the deck, to an anchor roller, to a bowsprit, or to a similar fixture. If an a-sail is tacked to the stem near the headstay tang, ‘TPS’ is nearly equal to ‘J’, the length of the foretriangle base. If an a-sail is tacked further forward to the end of an overhanging stem or to a bowsprit, ‘TPS’ will be significantly larger than ‘J’, the rated area of that a-sail will be bigger, and the rating will be faster. Under CRF the change in rating for increasing ‘TPS’ is generally in line with that of other handicapping systems.
A. This sail is by definition a headsail and not a spinnaker (See RRS 55.4), and CRF will rate it as a headsail. For such a sail, ‘IG’ would be declared as the vertical distance from the sheerline to the top of the sheave supporting its halyard, and not to the upper end of the nominal foretriangle headstay. Similarly, for such a sail, ‘J’ would be declared as the horizontal distance from the forward face of the mast to the attachment point for its tack on the deck or bowsprit, and not to the nominal forestay headstay tang at the deck. And finally, the LP of this sail would be the distance from its clew to its luff, measured perpendicular to the luff, and not the LP of a smaller sail set in the nominal foretriangle. Note that CRF will rate the speed potential of the boat with this sail in its best condition, and that the rating with such a sail will be ‘faster’ than it would be with a smaller headsail set in the nominal foretriangle, even when only that smaller sail is flown. Note further that the CYOA Classic Yacht Racing Guidelines require that such a headsail must have its luff attached to a stay, and that it cannot be set free flying
A. Under CRF, gaff headed mainsails in the SOT class will be rated as ‘square headed’. Exceptions to this approach are possible in cases where the sail configuration is very intentionally designed to have an entirely traditional appearance, with the gaff length on the order of 2/3 that of the boom length. However, any such exceptions shall only be made after special consideration by, and at the discretion of, the rating authority.
A. The height of a jib headed mainsail is declared as ‘P’, which is essentially the luff length of the sail. The height of a gaff headed mainsail is declared as ‘PG’, which is the height from the mainsail tack to either the peak halyard block, or to head of a topsail (if carried), whichever is higher.
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