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blueboy View Drop Down
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    Posted: 10 Nov 10 at 2:48pm
Originally posted by GK.LaserII

 
I see your point but this sounds like a fairly unique race Smile


Well FWIW, the huge Round the Island Race for yachts also almost always favours slow boats because they start later, go slower and therefore carry favourable tide for longer, whereas fast boats slog against tide most of the way around. Also starting later, they usually get more breeze. Something like 8 times out of 10 the Gold Roman Bowl (IRC overall prize) goes to a boat in the slowest class.

So maybe not an unique as all that for distance races to favour slower boats.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 10 Nov 10 at 2:14pm
I think it's a mistake to get too worked up about handicaps 
 
Agree but I like tinkering, also for me, it's about making the best of a bad situation.
 
The fast boats get to the far end of the course before the tide turns and then spend half the leg back slogging against the last of the flood. 
 
I see your point but this sounds like a fairly unique race Smile 
 
 
the advantages and disadvantages should even out.
 
That looks like the intuitive answer, unfortunately it's not the case. In the channel a boat spends about half the sailing season pushing and half being pushed. A slow boat looses a bigger percent of it's speed pushing and it has to do it for longer (compared to a fast boat), the speed is only partly regained when being pushed. Overall average for a season in tide a topper has between approx 8 and 10% extra penalty compared to a fast boat.


Edited by GK.LaserII - 10 Nov 10 at 2:19pm
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Posts: 1810 		Post Options Post Options   Quote craiggo Quote  Post ReplyReply Direct Link To This Post Posted: 10 Nov 10 at 1:14pm
It depends entirely on the course. We have long distance races at our club that massively favour the slower boats, as generally they arrive at the furthest mark up river, as the tide turns and are therefore in a favourable current for the whole race. The fast boats get to the far end of the course before the tide turns and then spend half the leg back slogging against the last of the flood.
Around the cans the effect is less noticable although, downwind legs against the tide will always favour boats with kites.
It must be remembered though that tactically positioning the boat in areas of weak tide makes a huge difference. At some point it is often worth ignoring the wind shifts and focus on the tide to get to the next mark quickest. As Blueboy says handicaps are a rough science, and it wont always be right, but if you run different courses throughout your season the advantages and disadvantages should even out.
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Posts: 512 		Post Options Post Options   Quote blueboy Quote  Post ReplyReply Direct Link To This Post Posted: 10 Nov 10 at 9:51am
Originally posted by GK.LaserII

(The views of those who race at HISC would be appreciated)


I'm a HISC member: I sail in a handicap class some of the time and OD others (some events we get a class start, some we don't).

I think it's a mistake to get too worked up about handicaps and  handicap racing. The reality is that it's a rough science and it's either your conditions or it isn't, especially where handicap bands are wide. There will always be races that benefit fast boats or slow boats, especially in tidal waters. You see the same in yacht racing.

That said, the HISC handicaps seem to work for us. We don't see particular classes as dominant or the opposite. We don't however have many very slow boats like Toppers doing general club racing. Chichester Harbour entrance isn't a very friendly place to sail such boats.





Edited by blueboy - 10 Nov 10 at 10:08am
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 09 Nov 10 at 12:36pm
Originally posted by Black no sugar

 
Our results guru explained the logic behind it in this document: http://www.lancingsc.org.uk/downloads/lcf_full.pdf 
 
To see the adjusted handicaps compared to PY in our club, have a look at http://www.lancingsc.org.uk/lcf_text.html
 
  
 
 
Well I'll be.....Hadn't seen Mikes calcs before but I have exactly (well, nearly) the same graph on my spreadsheet....The closer a boat speed gets to tide speed the curve goes up exponentially. Thanks for the link BNS, I shall ponder.
 
One arguement at the club is "what they loose uptide, they get back downtide".....unfortunately that is not the case Cry
 
We have some very good Topper sailors, a shame their skills aren't reflected in the club results.
 
I've been trying to compare results of tidal handicap opens with non tidal, the results I have are very suggestive, unfortunately I don't think I have enough data to solve the issue though.....do you think the RYA would share theirs LOL 
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Posts: 642 		Post Options Post Options   Quote Rockhopper Quote  Post ReplyReply Direct Link To This Post Posted: 09 Nov 10 at 12:20pm
at our club we sail in the afternoons on saturday and morning on the sundays so each day the tide is going in different direction which in turn levels out the adjustment needed some times we have up to three knots of tide which in you are say a topper is hard going but they still seem to do ok we dont have any really fast boats at our club the fastest one a rs 600 the rest seem to be vareos 2000s 200 and lasers and the odd topper.
So as for tide adjustment we dont bother but i think of next year we going to have personal handicap so mine in my vareo will i expect go down to 1015
Retired now after 35 seasons in a row and time for a rest.
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Posts: 3941 		Post Options Post Options   Quote Black no sugar Quote  Post ReplyReply Direct Link To This Post Posted: 09 Nov 10 at 10:32am
In our club, we have our own "Lancing Correction Factor" that we use for about half of the series in the calendar.
 
Our results guru explained the logic behind it in this document: http://www.lancingsc.org.uk/downloads/lcf_full.pdf 
 
To see the adjusted handicaps compared to PY in our club, have a look at http://www.lancingsc.org.uk/lcf_text.html
 
As a Topper sailor, I can say it works very well in light winds with reasonably flat water and tide. Add big waves to this and the Toppers don't stand a chance but that's due to a lack of pointy end rather than handicap adjustment!
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 08 Nov 10 at 3:25pm

I personally would like to advocate locally adjusted PYs but the "personal handicap" arguement against is a strong one IMO.

There are probably dozens of factors that can skew the PY at different locations but tidal effects seem to be one of the major issues, and, (possibly) one of the easier ones to deal with without resorting to personal handicap......again, your views on this would be gratefully received.

I've done a few sums and compared 9yrs of average tidal results against non tidal (comparing PY groups) and the results suggest that the closer boat speed gets to tide speed the bigger the handicap they suffer.....The slow boats get clobbered, no suprises there. The sums I did were crudely suggestive LOL but not very useful in any real sense.

I've taken a look at the HISC tide adjusted PY and am not sure that they've got it quite right...(The views of those who race at HISC would be appreciated) They've adjusted across the board but I reckon it just the slower boats that need a tweak.

http://www.hisc.co.uk/2010_handicap_description.pdf

Local tidal adjustment of PY is something I thought I would look into over the winter months, an ongoing project.

Has anyone else tried to adjust for tide? or looked at it? or got an opinion?
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