Why is the committee adjusting PY numbers at Chew?

The RYA Portsmouth Yardstick scheme is over 30 years old and is designed to support handicap racing between dinghies or yachts of different classes.  The handicaps or “Portsmouth Yardsticks” represent an average for the class over the whole range of sailing conditions.   The RYA refine the numbers annually, based upon returns from UK sailing clubs.   The adjustments tend to be very small and gradual and average out the performance of classes at clubs as diverse as Saltford on the river Avon, Frampton gravel pit, Chew Valley Lake and Portishead.   The RYA has long recognised that the average may not suit local conditions and their process recommends that clubs should adjust their numbers to reflect local experience. 

How are the Chew Numbers calculated?
The results for each race are analysed using a process described on the RYA website, which we have used for many years to calculate our annual handicap return.   The difference now is that we are actually applying these adjustments to create local numbers.   We have analysed the data for all handicap races at Chew since January 2008.   The data for each class of boats is aggregated to give the average adjustment to the class PY.   The RYA method is designed to remove poor performances such as boats which had gear failure or capsized a lot and in practice it uses the data from around 2/3 of finishers in each race.

How often are they updated?
We have refined the Chew Numbers several times since introducing them for the 2009 Frostbite series.  We regularly add in the data from new races but only adjust the handicaps twice a year - for the start of the Spring Series and again for the start of the Winter Series.

Isn’t this just Personal Handicapping?
There is a distinction to be made between setting personal handicaps (as in golf) and the effect of individual skill on the yardstick calculated for the class of boat.   The committee does not intend to create a system of personal handicaps at Chew, although we understand that other clubs are experimenting with this.  Our aim is to provide handicap numbers that reflect the expected performance of different classes on our lake.   It is inevitable that our data reflects the ability of the individual sailors at our club but we hope that in most classes there is a reasonable spread of ability across a number of crews, so that we get a fair average for the class.    The RYA method does include an optional mechanism to try to compensate for individual Crew Skill Factor.   This is not designed to create a personal handicap; rather, it is intended to reduce the impact that an individual sailor could have on the yardstick for a class, so the class handicap does not suffer because the national champion happens to sail at our club and wins all the races.

PY's for Club Use (Autumn 2011)

Peter Rose
CVLSC Handicap Fleet Captain