VSS uses the Performance Handicap Racing Fleet (PHRF) system. This is the most popular system for keel boats in use in the US. The PHRF system is administered by the US Sailing Association, our National Authority. The country is divided up into several regions and our local Authority is West Florida PHRF. If you want to race with VSS it would be best to join WFPHRF, but that is not absolutely necessary. We will be glad to assign a provisional PHRF rating; however, you would almost always get a more favorable rating by joining WFPHRF.
PHRF is normally uses the "Time-on-Distance" (TOD) method. Each boat is given several different ratings which may be different depending on the type of course sailed and whether or not she uses a spinnaker. Most of the races that VSS sets use the "random leg course (RLC)" ratings. These ratings have units of seconds/ nautical miles (s/nm). The idea is that we all race against an imaginary boat with a rating of "zero" (0) (we'll call that boat Rocket) and each boat's elapsed time in the race is "corrected" by subtracting the length of the course multiplied by its rating. If everyone sailed a perfect race in perfect conditions and if PHRF is perfect, then the corrected time of each boat would be the same as the elapsed time of Rocket.
To make the example concrete I will use my C&C 36 Summertime as an example. Her RLC Racer/Cruiser rating is 153, so if I sail a 10 nm course in 7200 s (that's 2 hours) my corrected time would be 7200s - 153s/nm x 10nm = 5670 s (1 hr, 34 m, 30s). Rocket would have to sail the course in less time than that to beat me. It should be noted that a boat may have a negative PHRF rating if the Rating Committee thinks she is faster than Rocket.
There is an alternative method of using PHRF ratings called Time-on-Time (TOT) that does not require knowing the length of the course. During the 2012-13 season we tried out the TOT system and it seemed to work better, in the sense that the fleet was compacted. That is, more boats seemed to do well with slower (high handicap) boats ending up at the front more frequently. I think most of us considered the experiment a success, so we score the entire season that way while displaying the TOD results so that people could compare them. Having not received and complaints I have now adopted the TOT method and, at least for now, I'm not displaying the TOD results, though they are being calculated for anyone who is curious about them.
The PHRF TOT system works like all of the the other handicapping systems that I'm familiar with. Each boat is assigned a Time Correction Factor (TCF) that is multiplied with her elapsed time around the course to provide a corrected time. The PHRF TOT system as recommended by US Sailing provides for adjustments for the average wind strength during the race. The formula for the Time Correction Factor is TCF = A/B+R, where A is an arbitrary number selected so that some middle boat has a TCF = 1.00000, B is a number that has different value depending on wind strength and R is the boats PHRF rating. I have selected A so the Summertime's (non-spinnaker) TCF is 1.0000. The values recommended by US Sailing for B, as well as the values of A to give (the non-spinnaker Summertime) a TCF of 1.0000 are:
Heavy/OWCW >16 knots, Force 5 and up665480
Average6< W <16 knots, Force 3 & 4734550
Light/All Up WindW < 6 knots, Force 0, 1, 2784600