Performance Handicap Racing Fleet (PHRF) is a handicapping system used for yacht racing in North America. 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 yacht in question should be behind the theoretical 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.
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.
The process of determining the PHRF for an individual boat begins with the regional PHRF rating, then adjustments are made for the individual attributes of the boat such as: modifications to the rig, the size of the largest foresail (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.