In handicap racing each boat has a rating that reflects her expected speed. Her elapsed time is multiplied by, or adjusted for, that rating to give a corrected time, and the boat with the best corrected time wins.
In a one-design class all boats are built to the same design and rules, so the first boat across the finishing line wins. Many club fleets, though, include boats of different sizes and types. Handicap racing lets them race fairly against each other.
Each boat is given a rating, a number that represents how fast she is expected to sail. After the race:
- the race committee records each boat's elapsed time, from the start to her finish;
- the elapsed time is converted to a corrected time using the rating. Most keelboat systems use time-on-time handicapping, where the elapsed time is multiplied by a time correction factor: a fast boat has a factor above 1, a slower boat below 1;
- results are ranked on corrected time.
Two broad kinds of handicap are used:
- Measurement and rule-based ratings, such as IRC and ORC, calculate a rating from the boat's measured dimensions, sails and weight. They are used for serious keelboat racing and offshore events.
- Performance handicaps, such as PHRF, are based on how the boat actually performs, and are adjusted from race to race according to results. In New Zealand, PHRF is widely used for club keelboat racing. Dinghy classes are often handicapped with yardstick numbers that work in a similar way.
Performance handicaps that adjust after each race reward improvement, so a new or less experienced crew can win on handicap, which makes club racing more open. The drawback is that a boat that sails well is given a harder handicap for the next race.
Some races use a pursuit or reverse handicap start, where slower boats start first and faster ones later, so in theory everyone finishes together and the first boat across the line wins.
Whatever the system, you are racing the clock as much as the boats around you, so keep sailing hard to the finish even when bigger boats are far ahead.
More in the book: Chapter 15, Your first race