New Posts New Posts RSS Feed: Grafham Grand Prix
  FAQ FAQ  Forum Search   Register Register  Login Login

Grafham Grand Prix
 Post Reply Post Reply Page  <1 56789 22>
Author
  Share Topic Share Topic  Topic Search Topic Search  Topic Options Topic Options
marke View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 16 Jun 08
Location: United Kingdom
Online Status: Offline
Posts: 211 		Post Options Post Options   Quote marke Quote  Post ReplyReply Direct Link To This Post Topic: Grafham Grand Prix
    Posted: 23 Dec 11 at 10:30am

Mike

I'm with Jim on this I do think you are being a little obtuse on this. I'm really not sure how much more transparency you want from the SailJuice people concerning their explanation - and this is from someone who sails a boat that got the biggest % hit in their numbers.


Just because the Laser sails well on handicap at a relatively small water like Burghfield it does not mean they have the right PY on open water. It seems to me that you are the one trying to twist statistics here.


From what I can see they have done exactly what the RYA recommends to overcome the known sampling issues with the full national database when applied to specific types of water (I believe the RYA are also trying to address this with future releases of the PYS system). In essence the "open water - non tidal" clubs running the main winter handicap races felt as a group that the standard PYs were not reflecting the performances of boats on their water. So they undertook a multi-year data analysis of their club results, and the results from past winter handicaps and came up with adjusted numbers (using the standard YR2 algorithm published by the RYA). They also compared them with results from some other open water clubs who were willing to share results to check their results. If the data analysis was consistent and indicated a change then a change was made, if the results were inconsistent or there was not enough data they didn't make a change.


As far as I can see they have done exactly what the RYA and many posters on this forum have been asking for - they made local adjustments to reflect their conditions, based on real data, using a published algorithm. Do you want them to publish all the data so you could do your own analysis - would be nice - but they are all volunteers and that takes time and money to do.


I did run three years of our data (open water - little tide)  past the Sailjuice numbers and where we had matching classes the numbers were pretty close - and very close for the laser and laser radial.


Mark



Edited by marke - 23 Dec 11 at 10:32am
Back to Top
Jon711 View Drop Down
Far too distracted from work
Far too distracted from work
Avatar

Joined: 04 May 07
Location: United Kingdom
Online Status: Offline
Posts: 465 		Post Options Post Options   Quote Jon711 Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 10:39am
Burghfield relatively small?? Have you ever sailed at Shotton, Ely, or my home club Broxbourne?? And there are many more around the country of similar size. To some of us Burghfield is huge, and Grafham, Rutland, et al are no different to sea sailing.....

Jon
Blaze 711
Back to Top
jeffers View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 29 Mar 04
Location: United Kingdom
Online Status: Offline
Posts: 3048 		Post Options Post Options   Quote jeffers Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 11:14am
Originally posted by Jon711

Burghfield relatively small?? Have you ever sailed at Shotton, Ely, or my home club Broxbourne?? And there are many more around the country of similar size. To some of us Burghfield is huge, and Grafham, Rutland, et al are no different to sea sailing.....

Jon
 
Do you still get Fiat Pandas dumped in the lake at Broxbourne? (mate of mine used to sail there and hit something, stopped dead and he got out and was stood on the roo of sail vehicle....
 
Try sailing at Welwyn Garden City (right next to the East Coast main line...looks more like a duck pond than a sailing club).
 
Anyway I digress....hats off to the SJ people for having the balls to have a play with the numbers.
 
They won't please everyone but they are having a go and it (appears) to be based on data rather than speculation for the most part.
Paul
----------------------
D-Zero GBR 74
Back to Top
marke View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 16 Jun 08
Location: United Kingdom
Online Status: Offline
Posts: 211 		Post Options Post Options   Quote marke Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 11:17am
Jon

Used to be a member of Burghfield and once tried to saila 49er there - so maybe you can see where I'm coming from when I talk about "small".

Mark
Back to Top
ex laser View Drop Down
Really should get out more
Really should get out more


Joined: 25 Mar 09
Online Status: Offline
Posts: 725 		Post Options Post Options   Quote ex laser Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 1:39pm
Originally posted by Jon711

Burghfield relatively small?? Have you ever sailed at Shotton, Ely, or my home club Broxbourne?? And there are many more around the country of similar size. To some of us Burghfield is huge, and Grafham, Rutland, et al are no different to sea sailing.....

Jon


+1
compared to where i sail, broxbourne is like the sea!!!!!!!!!!! LOL Wink


Edited by ex laser - 23 Dec 11 at 1:41pm
Back to Top
blaze720 View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 28 Sep 05
Location: United Kingdom
Online Status: Offline
Posts: 1635 		Post Options Post Options   Quote blaze720 Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 2:43pm
The key issue is not 'size' (!) perhaps but consistency - if you accept that consistent application of adjustment based on the numbers from the more open bits of water than you must surely also accept consistent application across ALL classes.  If its good for the goose what about the gander ?.  Asking for a bit of explanation and being largely stone-walled does not help or ensure general acceptance.  I've fully taken on board that Icon would start off 990 at these events given a lack of significant data for any new class like Icon, as I did when QMSC gave me 925 a few years back at the Bloody Mary with a prototype Halo rig (mightily flattered but still wincing there however  !).  But for classes with reasonable attendance at the GGP etc and therefore available track record it is I think quite reasonable to ask - What ? Why ? How ?  

I've no problem with Lasers or whatever if it can be shown they need 'relative help' ... but give us a bit of confidence in how adjustments are being made - ie short what criteria, data, fornula or even the 'fiddle factor' human assessment has been applied. 

The other point being floated around was that the adjustments were apparently based on the assumption of  'champion quality' helms in all classes as well in addition to the factor you mention that is 'open water' ... IF the top quartile or better of any class have simply not attended at all to race in these events in the past then historic results will naturally show any class so represented getting stuffed.  Open water may a factor of course, that is not being questioned and is very reasonable, but attending helm abilities I will argue will have a much greater impact.

It is not being obtuse, awkward or difficult at all to pose these questions.    What could be argued is a shame is the lack of a fullsome explanation.

Mike L.  
Back to Top
marke View Drop Down
Far too distracted from work
Far too distracted from work


Joined: 16 Jun 08
Location: United Kingdom
Online Status: Offline
Posts: 211 		Post Options Post Options   Quote marke Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 3:03pm
Mike

Its the YR2 algorithm (its published on the RYA site - or it used to be) - for the particpating clubs race data.  As far as I know changes only applied when there was sufficient data available.  I'm still not spotting the big secret ;-)

Mark
Back to Top
blaze720 View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 28 Sep 05
Location: United Kingdom
Online Status: Offline
Posts: 1635 		Post Options Post Options   Quote blaze720 Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 4:28pm
Well if YR2 is being used .. what data selection / manipulation was used to make the focus on  ? 1) Open Water (what exactly is 'open water' ?) 2) 'Champion Quality' only helming.  I'm not sure it could be used in a pure form to do this or without  'fiddle factors' - all that is being asked is the supply of a bit of detail - that is all !!  No witch hunt, teddies thrown out of prams or sour grapes.

No one is suggesting anything like a 'conspiracy' as Jim implies may be behind the motivation to ask.  Inconsistencies are much more likely to be due, in my experience, to the selection of data for inclusion and further are then as likely to bear some relation to plain old-fashioned 'cock-up theory' than to conspiracy !  The only other possible explanation for any apparent inconsistency is the application of 'additional human adjustment'.

But what on earth is wrong with the provision of a bit more detail ?  Or the simple request for it ?  As I said earlier in this thread even HMG's tax man gives an explanation - you may not like it of course, a different matter, but you do know exactly where you stand and that the next guy is subject to exactly the same treatment.

Mike L.
Back to Top
Jon711 View Drop Down
Far too distracted from work
Far too distracted from work
Avatar

Joined: 04 May 07
Location: United Kingdom
Online Status: Offline
Posts: 465 		Post Options Post Options   Quote Jon711 Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 5:03pm
Originally posted by blaze720

Well if YR2 is being used .. what data selection / manipulation was used to make the focus on  ? 1) Open Water (what exactly is 'open water' ?) 2) 'Champion Quality' only helming.  I'm not sure it could be used in a pure form to do this or without  'fiddle factors' - all that is being asked is the supply of a bit of detail - that is all !!  No witch hunt, teddies thrown out of prams or sour grapes.No one is suggesting anything like a 'conspiracy' as Jim implies may be behind the motivation to ask.  Inconsistencies are much more likely to be due, in my experience, to the selection of data for inclusion and further are then as likely to bear some relation to plain old-fashioned 'cock-up theory' than to conspiracy !  The only other possible explanation for any apparent inconsistency is the application of 'additional human adjustment'.But what on earth is wrong with the provision of a bit more detail ?  Or the simple request for it ?  As I said earlier in this thread even HMG's tax man gives an explanation - you may not like it of course, a different matter, but you do know exactly where you stand and that the next guy is subject to exactly the same treatment.Mike L.


Totally agree Mike, with the figures shown, and no explanation, how they were achieved few people are likely to turn up (Unless they have a Laser!).

I was seriously thinking of taking part this year, but with costs of travel, etc... To be tail end Charlie,.... NO CHANCE...

Jon
Blaze 711
Back to Top
blaze720 View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 28 Sep 05
Location: United Kingdom
Online Status: Offline
Posts: 1635 		Post Options Post Options   Quote blaze720 Quote  Post ReplyReply Direct Link To This Post Posted: 23 Dec 11 at 10:53pm
Hi Jon

If you are not going to the GGP or some of other events at least try and get to the Draycote Dash event at the end.  Cirrus have organised a first winter championship for the Blaze there for this year  (run within the 'main' event) and have put up a rarther nice bit of silver for the first 'Blaze Winter Champion' to take away.  Blazes were the largest class there last time (and have probably got nobbled on the PN as a result now !) but you will find excellent racing within the class regardless of the handicap distraction.  By all means question the 'adjustments' in the main but don't be put off racing your Blaze, within class, on those grounds.  We anticipate a good turnout there for sure and would love to see you join in as well.

Mike L.
Back to Top
 Post Reply Post Reply Page  <1 56789 22>

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz
Change your personal settings, or read our privacy policy