Since the first Atalantas were made they have competed against each other and against other yachts in races. When racing against other classes in races organised outside of the AOA they have typically used the organisers’ handicapping systems (e.g. Island Sailing Club, Portsmouth Yardstick and so on). When racing just against other Atalantas the Association has used its own correction factors.
This post details the AOA handicap correction factors. Further down the page you can see the basis for these handicaps, and read about handicapping in races organised outside of the AOA.
The new (2019) handicaps for AOA organised events
For racing in AOA organised races a series of handicaps were used and in particular a set developed by Dr Thursfield who used to own A52 Ecco and then A180 Stroller was used for decades. Unfortunately the full basis for these correction factors was lost.
Work has therefore been carried out to develop a new set of Correction Factors based on clear and proven rules, and covering all classes. The rules use key dimensions of the boats and sails to derive a ‘Base’ factor for each class. This is then modified as appropriate for different engine/prop configurations and for use of Spinnakers.
The above AOA Handicap factors are applied by multiplying the Elapsed Time for each boat in a race by the Correction Factor to give the Corrected Time. A lower Correction Factor indicates that the boat is slower.
The underlying calculations used to derive the AOA handicaps are based on the same principles as most modern handicapping systems. Specifically the handicapping formulae of the Old Gaffers Association (OGA) were plagiarised.
The key dimensions of the boats and sails used in the handicapping formulae are detailed below in feet and decimals of a foot:
The Foretriangle measurements I and J are explained in the diagram below:
The Foretriangle measurements I and J are explained in the diagram on the right.
Taking part on events organised by other organisations
The handicaps above are perfect for races involving only Atalantas (and are also pretty good for racing with the OGA) but will not be generally applicable in races organised outside of the AOA. The key for fair handicapping is that the Correction Factors for all boats are derived using the same formula. When racing in other organisations’ races it is most likely that they will want to derive a factor based on their roles using the standard dimensions in the table above, plus details of engine configuration and sails carried.
Once upon a time we were able to use Portsmouth Yardstick numbers as a pretty universal handicap. The Atalanta has a rating around 1250. However the old system has been completely overhauled by the RYA and the new ratings are based on racing results. We do not have a reliable set of PY numbers.