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AlexM View Drop Down
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Post Options Post Options   Quote AlexM Quote  Post ReplyReply Direct Link To This Post Posted: 16 Sep 12 at 5:21pm
Maybe.... but the 400 does well here too. But after trying to think of reasons I think we've just got a very good laser fleet (some clubs must have to keep the ave where it is)
We did a test on last series results with new and old handicaps and guess what it made little difference !
I've had a look around some of the clubs who are doing the new handicaps and what is clear is to expect the topper to move a lot next time!

Alex
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Post Options Post Options   Quote Oli Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 12:19pm
hi alex,
 
yes we made changes earlier in the year, as soon as a boat goes over 0.3cf we make sure that for the next series they use the new number. we now have 3 boats changed, fireball, musto and laser.  we still have a few members who dont like the changes, mostly those that it has affected yet mind, but we are getting there. 
 
ive only had a brief look at comparision results using new numbers and old for the same races and although not making huge changes (predicted it wouldnt make huge changes) it does make the racing closer and can mix it up a bit, which is good as it make syou try harder.
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Post Options Post Options   Quote Hector Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 2:01pm
Originally posted by AlexM

Have you started implementing them yet? We just started for autumn. Used the Yorkshire Dales SC format of dampening the changes.
Alex


For anyone wondering what the system Alex refers to is here at Yorkshire Dales SC,  See below from our website.

 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The RYA System also produces what they have called a confidence level.  'Confidence' refers to the stability of the number - not its accuracy. Confidence in the stability of PNs obviously rises as more race data is input and as we are in the first year of this process we decided to recognise the likelihood of increasing confidence, and so the Sailing Committee has agreed that the changes recommended by the RYA for YDSC will be 'damped' by applying  a % adjustment. Depending on the confidence level the % of any change applied will be as follows   

0.0 - 0.1 = 33.33%       0.2 - 0.3 = 66.67%       0.4 ++++ = 100%


RYA club specific PN list for Club Racing at Yorkshire Dales SC

                 
Data from 03/11 - 03/12  with resulting  RYA recommended PNs
                 
Class Appears Confidence Last used PN RYA Suggested PN Difference % of difference applied  'Damped' difference New YDSC PN
29ER
19
0 924 954 30 33%  10     934
CONTENDER 25 0 993 953 -40 33%  -13     980
FINN 43 0 1060 987 -73 33%  -24    1036
FIREBALL 11 0 980 967 -13 33%  -4     976
LASER RADIAL
56
0.1 1106 1162 56 33%  19    1125
LASER 217 0.4 1082 1087 5 100%  5    1087
MIRROR 25 0 1385 1389 4 33%  1    1386
MUSTO SKIFF 16 0 860 867 7 33%  2     862
PHANTOM
25
0 1030 1014 -16 33%  -5    1025
RS200 58 0.1 1057 1075 18 33%  6    1063
RS600 21 0 920 917 -3 33%  -1     919
RS800 23 0 822 801 -21 33%  -7     815
TOPPER 62 0.1 1297 1343 46 33%  15    1312
VORTEX
145
0.2 937 909 -28 67%  -19     918
                 

Classes not shown did not return enough data at YDSC to provide an accurate 'club' number. They will largely remain on the RYA 'standard'  number. The Sailing Committee reserve the right to adjust PNs in the interest of fair racing - for instance in the event of a boat new to the club with known performance characteristics that affect likely PN at Grimwith. Where possible, this will be done using reliable sources of data-led information.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The stand out change on our list is the Finn. It was one boat, very well sailed, and also a bit of a series picker. That is. did very well in Wed eve light winds, not so good in a breeze, but still beat 95% of Lasers, RS200 etc in wind.  A little worried that this was in effect a Personal Handicap, but thats a very good reason to 'damp' changes as we did.
The Topper had a big change, but that wasnt a suprise as they dont go well at our large windy venue. (And we have some very good Topper sailors).
Other big change was Vortex which went to 918 (damped from 908) whereas the Natonal PN for the Vortex is 945. They have still won probably 65% of races, and 75% of series, so we feel vindicated that our PN number is more accurate than the RYA number and is likely to drop further.
In general, the changes have made little difference to results, except the margins of victory / defeat have reduced, and the Lasers / Toppers get an occasional look in now.

Shortly going to update our numbers and will see if it goes where we expect  then, but also hoping for increased confidence with another seasons data.


Edited by Hector - 17 Sep 12 at 5:15pm
Keith
29er 661 (with my daughters / nephew)
49er 688 (with Phil P)
RS200 968
Vortex (occasionally)
Laser 2049XX
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andy101 View Drop Down
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Post Options Post Options   Quote andy101 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 2:12pm
Slightly suprised if it is a generally windy venue the radial moves up compared to the standard laser, I would have thought it would be the other way round as in my experience is radials struggle in the light stuff but go very well when the breeze picks up?
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Post Options Post Options   Quote Hector Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 2:17pm
All to do with who sails them.
In the Lasers we have a National Youth Squad member who was just top of his age group at the Europeans, 3 ex national Champions (not in a Laser, but top 5 in Laser Nats and race winner at Laser worlds etc), and many other very good sailors.
Radials tend to be beginners, kids coming up from Topper, Ladies who don't sail often and struggle when windy, and Old blokes trying to get more comfy!




Edited by Hector - 17 Sep 12 at 2:20pm
Keith
29er 661 (with my daughters / nephew)
49er 688 (with Phil P)
RS200 968
Vortex (occasionally)
Laser 2049XX
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Post Options Post Options   Quote marke Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 2:48pm
Hi

Keith's approach is a reasonable one - when applied to your own club data entered into the PYS.  It will take a little while for the confidence factor to be tuned on the website + since most clubs will not have a long period of data you can't take into periodic variations based on exactly who is sailing.

However I would not recommend applying it  to the annual national PNs published by the RYA, as you would be applying a damping factor on top of some inherent damping factors in the 'returns' based system.  As the use of the PYS increases and (hopefully soon) replaces the returns system then this caveat can be ignored.

Mark
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Post Options Post Options   Quote AlexM Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 3:05pm
Hi Keith
The only thing I didn't take from your dampening was those classes with a cf of zero, I thought it was too much of a personal h'cap. I.e. we'd have the 600 closer to a 1000
Alex
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Hector View Drop Down
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Post Options Post Options   Quote Hector Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 3:58pm
Originally posted by AlexM

Hi Keith
The only thing I didn't take from your dampening was those classes with a cf of zero, I thought it was too much of a personal h'cap. I.e. we'd have the 600 closer to a 1000
Alex


Catch 22 isn't it?
We have a very good Contender (another who's won a race at his worlds), the good Finn, the RS500 National Champion and a couple of other v good individual boats. To not change them at all on the basis of low confidence factor would penalise ( or advantage)  the boats with (slightly) higher factors that we have changed. 
The point as I understand it is that the computed figures are correct. The confidence level is low due to lack of data = far more likely to change compared to classes with more data, BUT the computed PNs are correct nonetheless.

I did an exercise using a few 'typical races' to illustrate to our members what actually happens in a typical race.
With say 20 boats out, the middle 2 or 3 boats sail roughly to their PN. The winner is roughly -80 below PN and the last is roughly +80 above PN. The spread reduces if the conditions don't favour one particular boat or type of boat too much, but increase if it's perfect for one type.
So with a spread of around 160 PN pts in most races, adjustments of +/- 20 pts don't necessarily move results very far.

What was illuminating was what actually happened with a boat that allegedly has extreme of performance such as the Vortex. When sailed by someone good in perfect F3 Vortex Conditions they can easily perform to a big reduced PN (say -100). The suprise was that they didn't lose by much in 'poor' Vortex conditions of F1 (roughly -20). IE they were rarely below half way and so their PN was almost always reduced. They would suffer more in near calm - but we don't get many of those, and if we do they rarely go out!
Taking an average sailor in an average performing boat (say an RS200). In lighter breeze, they would sometimes just get into the top half, sometimes not (largely dependent on beating most of the Lasers) and so would have a neutral PN. But in a stronger breeze our average RS sailor would struggle and be + 40 or 50 pts on their PN. Luckily we also have a top RS200 team who tend to balance that out so the RS200 number hardly changes at all.
So it's hugely to do with who sails what, and as such, we hope that the National database gets more accurate with more returns based on actual performances rather than the guesswork and fear of change / upsetting members thats previously prevailed.



Edited by Hector - 17 Sep 12 at 5:23pm
Keith
29er 661 (with my daughters / nephew)
49er 688 (with Phil P)
RS200 968
Vortex (occasionally)
Laser 2049XX
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Hector View Drop Down
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Post Options Post Options   Quote Hector Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 4:03pm
Should also point out that our results database was compromised last year due to issues with corrupted downloads and the fact that we used to allow multiple boats in a series. So someone who sailed the RS500 for 10 races then a Laser for one would get a result (for the series) with a boat labelled RS500/Laser. The PYS system didn't deal with that and so the entire number was compromised - hence only those boats with meaningful results in our table.
We've sorted that for this year and will have far more data as a result.


Edited by Hector - 17 Sep 12 at 4:12pm
Keith
29er 661 (with my daughters / nephew)
49er 688 (with Phil P)
RS200 968
Vortex (occasionally)
Laser 2049XX
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AlexM View Drop Down
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Post Options Post Options   Quote AlexM Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 12 at 4:22pm
Fair point, will have to consider for the winter series.
I've gone back to 2007 to get as many results on the web as possible ( adds a bit of more weight to the change )
Hopefully with the update we'll be able to share results with similar clubs. (how that is decided I'm not sure?)

Alex
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