CP-19's PHRF

[Craig Weis]

I read in Henry Cordova's piece on the beloved Com-Pac 19 in Good Old Boat Sept/Oct 2009 where the PHRF is 279. So what exactly does this mean? By the way Com-Pac 16 PHRF is 326.

Performance Handicap Racing Fleet (PHRF) is a handicapping system used in yacht racing. It allows dissimilar classes of sailboats to be raced against each other. The aim is to cancel out the inherent advantages and disadvantages of each class of boats, so that results reflect crew skill rather than equipment superiority.

PHRF is used mainly for larger sailboats (i.e., 7 meters and above). For dinghy racing, the Portsmouth yardstick handicapping system is more likely to be used.

The handicap number assigned to a class of yachts is based on the yacht's speed relative to a theoretical yacht with a rating of 0. A yacht's handicap, or rating, is the number of seconds per mile traveled that the theoretical yacht should be in front of or behind that yacht. Most boats have a positive PHRF rating, but some very fast boats have a negative PHRF rating. If Boat A has a PHRF rating of 15 and Boat B has a rating of 30 and they compete on a 1 mile course, Boat A should finish approximately 15 seconds in front of Boat B. Results are adjusted for handicap by the race committee after all competitors have finished.

Contents
1 Local Rules
2 Individual Boats
3 Flaws
4 History
5 See also
6 External links


Local Rules
Each region has its own variation on PHRF rules and ratings, based on local conditions. Here is an example of the Northern California PHRF Base Rating Report SAMPLE, the base rating is listed by boat in alphabetical order. The following is a sample of the Northern California rules for determining PHRF SAMPLE.

If a class of yachts is strongly outperforming their assigned rating, the PHRF committee of a region can adjust the handicap as they see appropriate. Hence PHRF is an observational rule as opposed to the IMS pure measurement rule. This prevents classes of yacht within a region from obtaining mistakenly favorable PHRF ratings and compromising the competitive nature of a fleet. All regions have slightly differing procedures for making changes but all have the same objective - keeping the racing fair for all.

Individual Boats
The process of determing the PHRF for an individual boat begins with the regional PHRF rating, then adjustments are made for the individual attributors of the boat such as: modifications to the rig, the size of the largest fore sail (jib or genoa), the size of the spinnakers, type of keel (full, fin, wing etc.), the number of blades on the propeller, and the style of the propeller (fixed, folding, feathering). Significant modifications to the mainsail can cause penalties.

A variant of PHRF racing is called a "pursuit race", where boats start in reverse PHRF order with the starting times staggered by the PHRF ratings. This means that the boats will cross the finish line in order of placement in the race.

Flaws
No rating rule is perfect and all have flaws. Alleged flaws to the PHRF rating system include;

An assumption that a rated boat is in bristol racing condition with a clean bottom, new sails and an experienced crew. This assumption excludes those with shallow pockets and experience from the winners circle and discourages many boats from racing. In fact the basis for a boats rating is that the boat is well prepped with good sails and competent crew makes it an effective club and local-regional handicapping system.

PHRF tends to be viewed as extremely political since rating values are perceived as very subjective and not based solely on empirical data. It is not an uncommon belief that the PHRF officials strongly influence ratings of their own boats to their favor. In reality decisions are made based on review of history and when there is a conflict of interest the PHRF official is not part of the decision process.

Design characteristics of boats yield different performance characteristics in various seas and winds. PHRF does not address these differences. The result is that it is not difficult to predict which boats have a better chance of winning based on conditions during a race. This is especially true where design characteristics are extremely different. An example would be a light displacement, planning hull verses a heavy displacement non-planning hull.

Where design characteristics are similar, PHRF is skewed to favor larger boats with longer waterlines.

What ever all that means.