Message #419 by: 
Posted on:  Tuesday 7th of January 2003 at 12:57 am
I sail an ancient Hobie14 Classic at Hythe (Southampton) S.C. I have downloaded the ISAF rating numbers which includes my boat. Fine, but the problem is that our club races assorted dinghies, and they use the Portsmouth Yardstick Numbers. This system no longer includes many good old boats, including the H14 Classic & Turbo due to lack of sufficient returns. The Classic was last shown in 1995 (PN 95) this was when "median" number was 100. The Turbo was last shown in 1996 (PN 875), the "median" number of 1000 started this year. The RYA conversion factor for old "100" numbers was not 10 but 9.462. So for the Classic the new number became 95 x 9.462 = 899, rounded up, to the nearest whole number. For the Turbo, if it had not been included in 1996, it would have converted to 92 x 9.462 = 871 (92 was the 1995 PN), bt it became 875, so presumably there was a small adjustment. Similarly the H16's 1995 PN of 85 would have converted to 804, but in fact was listed as 802 in 1996.
I am concerned that my PN is getting rather out of date, but I think most monohull dinghy clubs still use the Portsmouth system, or am I wrong? Is there any available formula to convert ISAF numbers to PY numbers? I have fiddled about but can find no relationship which accurately converts the H14C, H14T, & H16 back PN's for mixed fleet racing in clubs still using this system. Perhaps I should just drop my 899 number by three in line with the Turbo, but it's number is pretty ancient too! '3' on the "1000" numbers divided by 9.462 is only '0.32' on the old "100" numbers so would not have shown anyway.
I notice that Texel numbers seem to be pretty close to 100 x ISAF numbers.
Any thoughts would be appreciated.
Regards, Nick

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Messages in this thread:
Handicapping by Nick Hardacre on 07.01.2003
     Handicapping by viv nichols on 07.01.2003
          Handicapping by Nick Hardacre on 09.01.2003
               handicaps by chris browning on 13.03.2003
     Handicaping by Ian Craven on 08.01.2003
          Handicapping by Nick Hardacre on 09.01.2003
     h'cap by Richard Heaton on 30.06.2004

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