ORC Club Graphic Depiction of the line defined by the formula:

Corrected Time = (PLT x Elapsed Time) – (PLD x Distance)

ORC Club uses a boat’s hull design and sail measurements to arrive at polars that predict how a boat will perform in differing wind and at different points of sail.  By contrast, PHRF uses observed performance to predict how a boat will perform in 12 knots on a windward leeward course; if a boat does not race under those conditions, the PHRF predictions may be off, because there is no observable performance data to rely upon, and the predictions do not work as well when the wind velocity or course configuration is different.