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Ssssslow boats in tide.......

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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 11 Nov 10 at 10:26am

Originally posted by craiggo

Having been responsible for the returns at our club for pretty much 10years, I've seen the impact of tide after all we do sail on the seconds most tidela stretch of water in the world!

We hold a series of long distance dinghy races where we see this effect. Its rare that fast boats win unless the wind direction is unusual or there are large fluctuations in wind strength.

For normal round the cans racing we do see everything averaging out.

.
 
 Interesting stretch of water..and it's good to see you have some races that favour the slow boats. As I said earlier, we have some good Topper sailors that seldom do well in the club results thet'd love your place LOL.
 
It's difficult to work out if there is any tidal disadvantage for slow boats from 1 series at 1 club because crew skill can't be averaged out and there is just not enough data.
Although I just had a quick shufty at your summer series slow handicap and the 3 boats with the lowest py (i.e. fastest) have done significantly better as a group than the slowest group on average. They've all done a different number of races though so it's pretty meaningless.
 
Maybe coastal clubs could  split their results into fast medium and slow, or fast and slow as you have done, it does reduce some of the tidal bias.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 12 Nov 10 at 12:50pm
Originally posted by Black no sugar

In our club, we have our own "Lancing Correction Factor" that we use for about half of the series in the calendar
 
 
How was the system received by your sailors?
 
 

Some findings from 13 tidal and 13 non tidal results. I steered clear of small gusty lakes, they don't tend to have fast boats on them anyway. More data would be good.

No tidal........slow boats average results are 3% poorer than fast boats
Tidal...........slow boats average results are 11% poorer ditto.


It would seem from these figure that HISC and Lancing are on the right track. I rarely sail on lakes so it could be down to other unknown (by me)  factors...... Or it could be down to bad maths LOL 



Edited by GK.LaserII - 12 Nov 10 at 7:54pm
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Post Options Post Options   Quote Black no sugar Quote  Post ReplyReply Direct Link To This Post Posted: 12 Nov 10 at 2:10pm
Originally posted by GK.LaserII

Originally posted by Black no sugar

In our club, we have our own "Lancing Correction Factor" that we use for about half of the series in the calendar (strangely, 'calendar' became 'calender' in the quote, argh...)
 
 
How was the system received by your sailors?
 
 

Some findings from 13 tidal and 13 non tidal results. I steered clear of small gusty lakes, they don't tend to have fast boats on them anyway. More data would be good.

No tidal........slow boats average results are 3% poorer than fast boats
Tidal...........slow boats average results are 11% poorer ditto.


It would seem from these figure that HISC and Lancing are on the right track. I rarely sail on lakes so it could be down to other unknown (by me)  factors...... Or it could be down to bad maths LOL 

Most sailors are quite happy with Lancing Correction Factor. The handicap allocated in LCF for the fast fleet boats is close enough to PY not to make a significant difference within the fleet. Streakers, Toppers and Picos are happy Tongue
 
We had a couple of negative comments from sailors who consider that any deviation from PY is a heresy... Mike and others have explained that local variations in handicaps are encouraged by the RYA and that the PY handcaps are calculated in a similar way, on a much bigger scale.
 
There is of course the problem of small classes where it is difficult to find a happy medium. In our club, we have three Streakers going out reasonably regularly: 2 of them are wooden boats, older style, and only sail in only in good weather. The more regular Streaker sailor has a very nice shiny Rooster and, because he sails more often than the other two, it could upset the rationale in calculating the LCF handicaps for the class, giving a disadvantage to the other two.
 
That's when you have to trust the results guru's integrity and, at Lancing SC, we have no problem with this. What Mike says is right!  Smile  
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 12 Nov 10 at 7:53pm
Sorry BNS, I clipped the last 2 letters of calendar when I chopped your quote up, I put them back wrong Embarrassed. I'll put it right.
 
As for your results Guru: Every club should have one. 
 
 I think doing a tidal adjustment at our club would meet some resistance, still worth a try though, I might be surprised.
 
 
 
 
 
 


Edited by GK.LaserII - 12 Nov 10 at 7:59pm
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 10 at 1:03pm
Making progress.
 
I've been looking at results till I've gone cross eyed......90% of the time I can tell now , just by looking at result sheets whether they're tidal or non tidal.
 
Non tidal = 3% variation between fast and slow boats ,indicating that the PY seems to work quite well in these conditions.
 
Tidal = 8.3% variation (for an Opti read 10% on a projection), indicating that the PY is possibly miles out in these conditions.
 
The medium boats did best in both locations but only slightly in tidal.
 
The RYA are never going to get it right for both locations, not on one set of figures..........Since club class racing isn't likely to have a resurgence anytime soon, local adjustment (as the RYA encourage) seems the way to go.


Edited by GK.LaserII - 22 Nov 10 at 1:14pm
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 10 at 3:21pm
If the RYAs PY numbers are based on an avaerage of all locations, and if returns are split roughly 50/50 tidal/non tidal then shouldn't the tidal and non-tidal values be equally (but opposite) varied? On the one hand it sounds like you are suggesting that fast boats are favoured in all locations, but then you say that medium boats are favoured in all cases. Have I misunderstood? Sorry for the poor grammar- don't want to be timed out!   
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 10 at 3:50pm
If the RYAs PY numbers are based on an avaerage of all locations, and if returns are split roughly 50/50 tidal/non tidal then shouldn't the tidal and non-tidal values be equally (but opposite) varied
 
That's what I thought I'd find but the results from the races I've looked at suggest otherwise. I really don't know why....are most returns from lakes??
 
The figures I gave indicate the difference between fast and slow but the medium boats do better than the fast in both situations overall (only very slightly on tidal less than 1% which means it's probably worth ignoring)......it's interesting that the dip for medium is present in both though.
 
Some medium boats had quite a py trim this year and that may take the medium dip out. It could be also (i suspect) that on average the medium sailors are of better quality..... skill factor, so the dip should be there.
 


Edited by GK.LaserII - 22 Nov 10 at 3:59pm
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 24 Nov 10 at 8:57am
 
Going
 
 
Going
 
 
Going
 
 
Gone
 
Geek


Edited by GK.LaserII - 24 Nov 10 at 3:50pm
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