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Quick PY Question

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pondmonkey View Drop Down
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    Posted: 11 Jan 13 at 3:33pm
Originally posted by iGRF

As I said, the handicap should be the choice of the sailor not some autonomous body that keeps getting it wrong,

Last time I checked it was.   After all what is a sailing club if it is not a group of sailors?  

If your specific group of sailors cannot or will not change the recommended yardstick to suit your waters, your skills mix and your physical attributes, then frankly what do you expect the RYA to do about it?

They tell you to change them, you choose not to.  Now if you're prepared to change them, but the rest of the club isn't... well really there's only two options- find a new group of sailors or put up with it.  

It really is that simple.  
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 3:42pm
Originally posted by jeffers

PY works well if you all take it as a bit of a laugh and not too seriously.
As for a fair course I always try to get 2 beats, 2 reaches (1 tight 1 broad) and a run in to a course. That way one boat is not usually favoured over another.
Course content does make a surprising difference.
And as for all those who say 1 point of PY does not make a difference we had 4 in different classes separated by 1 second each a couple of weekends back. 1 point of PY for any of them would have made a difference to their finishing places,
As for the PYAG group they are doing a great job.
For those who say 'how do I get my club to change?' get on you sailing committee and raise it. This is what we did at Hunts and a couple of PYs were changed and, as a result, the racing has become far more active. In reality the PY changes made little difference to the series results but it gave people the perception that they had a chance so they would come and give it a go.
and GRF...quick PY question....2 mutually exclusive terms....


Agree with that apart from the bit in bold. You could pick 4 digit PY's out of a hat and at some point you would have a race where 4 boats were seperated by one second each. The fourth digit is only more precise than the old three digit system, *if you have confidence that you can measure performance to that level of precision*. For example, we can have a lot, maybe 100%, confidence that a boat's true PY should be somewhere between 950 and 1050 (or 95 and 105 in a re-based system). We can still be, say, 90% sure that it lies between 970 and 1030. But you must have less confidence (70%?) that it lies between 995 and 1005, and less still (30%)that it ies between 999 and 1001. So by pretending to increase precision, you are actually reducing confidence in the result. To put it into perspective, a doppler shift GPS speedometer, like a Speedpuck, has a quoted accuracy of +/- 0.2kts. At an average speed of 4kts, that is an accuracy of 5%. The fourth digit on a PY number implies an accuracy of 0.1%!
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:23pm
Even in the best circumstances, PY is not precise to better than 1%.
But over a series, only a few races are usually that close, you are far more likely to have 2 RS400's finishing withing 30 seconds than to be within 30 seconds of the other comparable classes.

But on our courses, it is very rare for two boats of the same class to finish closer than 15 seconds, because once one boat has to follow the other around a mark, the lead is one boat length minimum. Like many clubs, we don't have a nice open beat to the line, the last leg is usually a drag race.

Any PY result closer than 20 seconds is morally a draw or a random act, better luck next time.
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Post Options Post Options   Quote Oli Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:39pm

we have made some substantial changes at my club over the last couple of years, firstly we changed the courses that were created 15 plus years ago when most of the boats racing had symmetric kites and the py differences between them was much narrower (505 at the top end vs a merlin in the fast fleet). We had 64 course variations! We now have more asymmetrics sailing and the py bands are the same for the fleet splits but difference in py is vast (moth vs merlin), so after tracking races with gps for a season or so we could see where boats were gaining advantage and how we could minimise this. I wont bore you with the details but it led to boats not turning up if the wind was in a certain direction as it was a foregone conclusion. Having made the course adjustments and removing the our windward leeward courses too (not favoured much by the symmetric boats surprisingly) we have come down to 48 standard courses that have much more balance between reaching and running with truer beats too. Just doing this alone has decreased the average corrected result times between first and last by about 10%.


our next step was to introduce py adjustment throughout the season. We used to do our returns as most clubs did/do without much if any adjustment at all. With the new pys site we have the confidence to, when the confidence factor is high enough, to change a py for the next series. We can do this because no body is guessing at what the number should be, no one can manipulate the number once the result is in, its a case of if you have sailed as a class to that handicap that then thats the handicap you are given for the next series. As an example the fireball has moved from 982 down to 969, the musto skiff has come from 860 to 842 via 838. most people have been happy with this system because its live and doesn't have some person tweaking it for personal gain. The next big move would be to our blaze fleet, they move from 1040 to 999 which although is a big move when you look back at their results over the last year and replace the handicap with the new one, they still fair pretty well, I would guess the number to settle around 1010 over the season, so they will have to take a hit to begin with. The nice thing is it will only be 999 for one series so the complaints shouldn't last too long, if at all if they keep winning at that py.


The idea for these changes wasn't to stop people from winning but to reduce the gap between people of similar abilities in different boats, which with the old system wasn't happening. We are also going to run a personal handicap series for a bit of fun later in the year and see how that turns out.


We have had mostly positive responses from the sailors about these changes and any gripes about courses before a race are usually quashed afterwards by the grins on their faces. We do get some complaints of being biased with py, but as we point out, the numbers used are the numbers we have sailed to and nothing more.

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Post Options Post Options   Quote ChrisJ Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:40pm
>>Any PY result closer than 20 seconds is...
... An encouragement to sort out that one bad tack you made, and make sure you don't do it again next time.
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:44pm
Anarchy - so now we can have clubs competing for boats by giving them a more favorable handicap..

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Post Options Post Options   Quote pondmonkey Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:52pm
Originally posted by iGRF

Anarchy - so now we can have clubs competing for boats by giving them a more favorable handicap..


as opposed to clubs competing for sailors by saying... 'hey look, we run class racing and PY racing, and guess what, we even run the PY racing properly!!!'
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Post Options Post Options   Quote Oli Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 4:59pm
we dont give anyone a handicap, favourable or otherwise, and its not about getting people to turn up to increase revenue (we dont run our bar for profit), we also have a very healthy membership (smallish river club with 1000+ membership.  its about people enjoying their sailing, and if you cant race because of wind direction or banditry then you dont enjoy your time on the water.  we are very much an old school of thought club, members run every aspect of the club, massive volunteer base to keep things progressing.  we now have a more consistant turn out for each series with people coming off the water having enjoyed their time and actually no mention of py banditry afterwards, very refreshing.

Edited by slop_idol - 11 Jan 13 at 5:01pm
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 5:06pm
Originally posted by slop_idol

...... The next big move would be to our blaze fleet, they move from 1040 to 999 which although is a big move when you look back at their results over the last year and replace the handicap with the new one, they still fair pretty well, I would guess the number to settle around 1010 over the season, so they will have to take a hit to begin with. The nice thing is it will only be 999 for one series so the complaints shouldn't last too long,.....


So you are going to change to a number you believe to be wrong?

The more you fiddle with the numbers, the more people will realise they are founded on very little.
If random local fiddling with the PY's takes hold, PY racing will be greatly damaged within a few seasons.
People will quaetion the numbers a lot more and the results will have no credibility.

If you believe the right answer really is 1010, you should not start by over-correcting.
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Post Options Post Options   Quote Oli Quote  Post ReplyReply Direct Link To This Post Posted: 11 Jan 13 at 5:11pm
Originally posted by RS400atC

Originally posted by slop_idol

...... The next big move would be to our blaze fleet, they move from 1040 to 999 which although is a big move when you look back at their results over the last year and replace the handicap with the new one, they still fair pretty well, I would guess the number to settle around 1010 over the season, so they will have to take a hit to begin with. The nice thing is it will only be 999 for one series so the complaints shouldn't last too long,.....


So you are going to change to a number you believe to be wrong?

The more you fiddle with the numbers, the more people will realise they are founded on very little.
If random local fiddling with the PY's takes hold, PY racing will be greatly damaged within a few seasons.
People will quaetion the numbers a lot more and the results will have no credibility.

If you believe the right answer really is 1010, you should not start by over-correcting.
 
we have seen most of the numbers stabilising (fireball around 969-973, and musto from 838 - 842) so we have that covered in as much as once it reaches a very high confidence factor and the movement is minimal the number will be set until ultimately we have locally adjusted numbers for all classes sailed at the club.  i fail to see how this will put people off, being proactive and adjusting numbers that have been wrong for a long time and correcting them can only be good for everyone surely?
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