As previously reported, the 2010 rating will be based on the PHRF Downwind rating and on ORR. Below is the text of the ratings system. The ORR scaling factor has changed from .84 to .83 to better align the two systems.
Ratings for PHRF based yachts:
For yachts competing under a Northern California PHRF certificate, the PCR (Pacific Cup Rating) will use the new “downwind rating” found on 2010 NCPHRF certificates.
PCR = “downwind rating” + 515
The 515 correction converts the downwind rating into a predicted average speed in seconds per mile that the boat is expected to sail for the course. Note that this does not affect time deltas or results between PHRF based boats.
Ratings for ORR based yachts:
For yachts competing under an ORR certificate, the PCR is calculated using the US Sailing ORR VPP with a Pacific Cup wind mix applied as follows:
|
True Wind Angle |
True Wind |
Distance |
|
Degrees |
Knots |
Miles |
|
Opt. Beat |
16 |
6 |
|
Opt. Beat |
20 |
8 |
|
52 |
16 |
14 |
|
52 |
20 |
22 |
|
60 |
20 |
75 |
|
75 |
20 |
150 |
|
75 |
24 |
75 |
|
90 |
16 |
70 |
|
110 |
16 |
70 |
|
110 |
20 |
50 |
|
120 |
12 |
50 |
|
120 |
16 |
10 |
|
135 |
10 |
100 |
|
150 |
12 |
115 |
|
150 |
20 |
240 |
|
150 |
24 |
100 |
|
Opt. Run |
6 |
20 |
|
Opt. Run |
8 |
40 |
|
Opt. Run |
10 |
80 |
|
Opt. Run |
12 |
120 |
|
Opt. Run |
16 |
135 |
|
Opt. Run |
20 |
300 |
|
Opt. Run |
24 |
220 |
In the table above “Opt. Beat” is the boat’s optimum wind angle for upwind sailing for the specified wind speed, per the ORR VPP. Similarly “Opt. Run” is the optimum wind angle downwind sailing.
The result of the above calculation appears on the ORR certificate as “Pacific Cup TOD”
PCR = “Pacific Cup TOD” / .83
The wind matrix is for “typical” Pacific Cup conditions in a year with good breeze and a 2070 nm course length. The denominator of .83 corrects for the fact that wind is often lighter and boat always sail further than the great circle course length.
