Author Topic: The Bloody Mary  (Read 21671 times)

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Offline TSC

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Re: The Bloody Mary
« Reply #15 on: December 16, 2011, 02:02:58 PM »
Not a typo Roland, just down to insufficient statistical data to generate a sensible number. The Winter series results haven't been included yet so that will pull the number back up a bit.

Paul

Offline phil_kirk

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Re: The Bloody Mary
« Reply #16 on: December 24, 2011, 03:09:58 PM »
As you may have seen in the BM NOR the cherubs start 1 minute in front of the B14.  Now as I recall the leading boats at the inlands where keeping up with the leading boats in the B14 fleet.  So for a bigger course with fewer hoists and drops this may actually be quite close. 
Sarah and I have noticed that on bigger courses at Thornbury I.e. our longer distance races we can be nearer the RS700's than we can on a normal club course. Taking some of the manoeuvers out makes a difference.

i would like to be in an ent at the grafham grand prix though as they have increased the PY to 1130 from the RYA's 1117. 

Offline andy_peters

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Re: The Bloody Mary
« Reply #17 on: December 29, 2011, 04:22:25 PM »
All, thought you may be interested in the reply from the handicapers at the BM - they have asked me to point out the comments are for the BM handicap - not the whole Sailjuice series.  They are very keen for Cherubs to participate in the BM and help generate data for future years handicaps.  I hope to sail (but that does depend upon persuading a certain lady that sailing in January isn't cold!)

Andrew,

First let me introduce myself, for my sins I am Principal Race Officer for QMSC and, more to the point, I have been working with Andrew Craig for the last few years to bring fairer sailing to QM. I am sure you will agree that the RYA Portsmouth Yardstick had become ineffective at producing fair sailing, particularly at QM as it was based on data received and a great deal of that was inaccurate or from waters that have very different sailing conditions to ours eg rivers or tidal waters. This started with Andrew crunching a vast amount of data which broadly showed that fast boats were generously treated and slow boats harshly by the PYS. This was epitomised by the Laser which although we have the best Laser fleet in the UK and some great sailors, including Olympic aspirants they never won the Wednesday Evening Series. So what we have done is slowly but steadily rebalance the QM handicaps and this has resulted in a much broader range of boats finishing in the top 10 of the Wednesday Evening Series. Clearly you have to have the wisdom of Solomon and the skin of a rhino to take on this task but I am very proud of what Andrew with a little help from myself has achieved.

Turning to the Bloody Mary we first established that this is different from Club Racing – in particular the nature of the course we need to set means it has generally a higher proportion of downwind sailing. Additionally boats with tall rigs can pass slower boats more easily than boats of similar sail area with shorter rigs – obviously the ability to pass slower boats is key to success at the BM. Historically the Bloody Mary used Portsmouth Yardsticks with ourselves only filling in the gaps where a PYS did not exist – this tended to favour certain class, particularly development classes, as epitomised by the National 12 and the International 14, where developments kept the class way ahead of the PYS due to the lag in data coming in, the slow response of the handicapping system and only annual publication of changes. Incidently only a boat with a published PYS could win the Trophy in those days. A few years ago the ethos of the BM was changed and winning opened up to all classes, hence we decided to set our own BM handicaps. Andrew and I used the historical BM data to start developing special BM handicaps – rhino skin became particularly important as we now suffered from “feedback” from online forums as well as direct from competitors! With the creation of the SailJuice Global Warmup we saw a benefit of sharing and hence increasing the data with other “great lake” clubs and Andrew met with them at the Dinghy Show this year to start that process. Whilst no club is bound by the shared figures we have moved much closer together and made a major step in making the racing as fair as possible. Clearly it will never be perfectly fair – the foiling Moth being the prime example of giving a handicap for classes where performance varies dramatically depending on the conditions on the day. Most competitors understand this and some are known to have a few boats to choose from and only decide once they have a weather forecast available – but such is the nature of the event.

So to the Cherub – this creates two difficulties for us handicappers, namely little relevant data is available relative to the bigger classes and it is a development class so even where data is available one has to allow for the class making major improvements. We are trying to handicap to each class in best conditions with top sailors – putting all this together we have actually set the Cherub at 860 for the 2012 Bloody Mary – I can hear the screams of rage as you read this but we think it is fair. Clearly it is your decision whether to sail or not but I urge you and other Cherubs to turn out for 2012 BM and give us hard, relevant data, without this we are left to interpolate the data we have and fit it to that of other classes.

I will be assistant Race Director this year and would be very happy to discuss the issue with you over a pint after the finish.

Finally I am very happy that QMSC has been at the forefront of handicapping in the UK and am proud of the handicaps we now use – we know they can be improved and will no doubt be carrying out major analysis after the 2012 event.

Paul Schroeder

PRO QMSC


Offline Phil Alderson

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Re: The Bloody Mary
« Reply #18 on: December 30, 2011, 10:14:42 AM »
Good that you got a response, however it is rather high on words and low on information.
I wonder if they are using the 860 number as the base when they recalculate the numbers.

My understanding of the Portsmouth system is that when you recalculate the numbers you are supposed to exclude those who have had a very poor performance, which is OK as you don't want to include those who spent half the race upside-down.
However if you are using too low a number for the base you end up throwing out the average performers and only including the exceptionally good ones. This then drops the handicap further. Where you have a class with variable performance like the Cherub things could be even worse. 
They may have taken all this into account in their deliberations but their answer does not say whether they have or not.

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Offline Graham Bridle

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Re: The Bloody Mary
« Reply #19 on: December 30, 2011, 12:04:38 PM »
I agree with Phil that its nice to get a response, seems to me that whats being said is that each property they think the cherub (as a development class without a fixed PY) posesses e.g "good downwind speed" and "tall rigs for overtaking" = X PY points off.

All very arbitary, I wonder if there are other classes effected in the same way ? I do feel that X has come out rather large in their calculations.

When all is said and done, we do need to give them hard data so people in the top half or so at the nationals post results in the low end of the fleet, that gives us leverage next year to request a rethink, course if we go and win then we wont need to request anything as it'll soon be moved again ! The other benefit is the more of these we do, the more likeley w may get a permanent PY which would be an asset to the class as a whole.

I feel a strong obligation to go, however I cant persuade Eddie as he is a complete tart when it comes to sailing in the cold, and at the moment I have done my back to the point I could hardly get there let alone cherub sail, anyone else up for it ?

Offline phil_kirk

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Re: The Bloody Mary
« Reply #20 on: December 30, 2011, 06:45:53 PM »
Looks like the conditions are likely to be mid teens to mid 20 knots for the BM so powered to overpowered conditions. So the cherubs should sailing to the max. But we will be trying to minimise manoeuvres and will be at the mercy of wind shifts and shadows.

While we may have slightly taller rigs (the cherub mast is 30cm taller than the ent mast, both are deck stepped) so the advantage may not be great.
Where i think we will loose out is in the last 1/4 of the race when we start overtaking slower boats. This is because the slower boats will be more manueuvrable than the cherub making it difficult for cherubs to commit to crowded mark roundings whilst avoiding other boats. having to possibly sail the long way round, then find clear air then catch back up with the laser we were previously next to will result in slow progress.

We will benifit when the finish is sounded if we are a way from the nearest finish line. This is a point where slower boats loose out and the handicaps should reflect this.

Happy to create some data and take part and will be interested in how we get on.


 

Offline JimC

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Re: The Bloody Mary
« Reply #21 on: December 30, 2011, 10:24:32 PM »
I found the analysis I did after the 2004 Champs where all the races were timed...

I calculated Dangerous Beans, Kevin's uprigged and two stringed Slug, to be running an equiv PY of 880-890. It would be rather disappointing if you guys aren't going faster now.
I won't bore you with the whole thing of how I converted achieved peformance into a PY but these were the actual performances of the individual boats at the sharp end of the fleet. Its striking just how big the differences in performance between individual craft are: the odd 10 or even 20 points of handicap mean very little compared to how well the crew is doing.
2676/8 2681/2 were all full on 97 rules boats, but I always thought that the sails 2682 had for that event were very inferior to the originals.
2641 and 2662 were fully converted to 97 format, IIRC 2637 was not fully 97 rules at that time, or at least not with sails cut for the mast in use.

But chaps, if you want better PY data, get out there and sail your boats every week at your local club, and if necessary volunteer to do the club returns. Obviously so much the better if you are members at the clubs that do the Sailjuice events.

If you want my honest opinion as to why Andy and Alex were so very fast at those Champs, it was because they were out sailing every week, and most of the rest of us about once a month. I reckon that's worth a good 30 or 40 points of PY at least.

Boat/Design/Sailor                       Notional PY 
Slug/12ft skiff #2/Simon Roberts          807
2673 DBeans/Slug – big rig/Kevin Ellway   829
2676 Shiny Beast/Paterson 7/Andy Paterson 873
2682 Mango Jam/ButtPlug/Gavin Sims        920
2678 LRN/Paterson 7/Patrick Cunningham    946
2681 Aqua Marina/Paterson 7/Phil Alderson 948
2662 Fizzy Shark/Pasta Frenzy/Tim Dean    965
2641 Halo Jones/Bistro/Alex Adams         973
2637 Norwegian Blue/Bistro/Will Lee      1008


Dbeans: White sails =15sqm, spinny=23sqm.

Slug: Whitesails = 17sqm, spinny = 33 sqm.
« Last Edit: December 30, 2011, 11:12:34 PM by JimC »

Offline Phil Alderson

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Re: The Bloody Mary
« Reply #22 on: December 31, 2011, 10:52:17 AM »
Jim I can see how you can get a spread of handicaps from a single class fleet, but without a reasonably reliable benchmark how do you know that the 920 of Mango Jam was equivalent to an RS600?

When I looked at handicaps in 2008 based on peoples race results I got higher numbers, and the average I got is not too far away from what the RYA is currently suggesting.


See the chart I produced which can also be seen in this topic: http://www.sailingsource.com/cherub/forum/index.php/topic,59.msg532.html#msg532


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Offline JimC

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Re: The Bloody Mary
« Reply #23 on: December 31, 2011, 06:56:40 PM »
without a reasonably reliable benchmark how do you know that the 920 of Mango Jam was equivalent to an RS600?
Long time ago now, but if I recall the results came with one of those back calculation figures and it was zeroing against that...
But the way I got the 880-890 figure was slightly different. As I recall I did an estimate of where I felt Kevin and Jo would have come in the fleet, sailing as they were and bearing in mind Kevin's past Champ results. That gave me a reasonable estimate of where in the heirarchy between AndyP and the likes off Alex and I I estimate they would have finished sailing the boat in 97 rules format. That gave me one number. I then took the offset between that number and the one they actually recorded, took that away from the then current Cherub PY, and that's where I got 880-890 from.  So to a good extent it doesn't matter how accurate the benchmark was in those numbers, because what mattered was the offset. The  accuracy of the then RYA handicap was much more to the point, but I think we felt it wasn't bad at the time.

Still, if you want to see a really good example of throwing your toys out of the pram and making your fleet look bad, take a look at the 5:55pm post in the YY Grafham Grand Prix topic.

The guys in this handicap are trying something different, and why not. I can bore for England on the subject of handicaps, but some of them are very difficult. The Laser, for instance, is a major pain. We have some pretty good Laser sailors at our club, and they don't win nearly enough races on handicap compared to how well they do at worlds against other classes. But if you set a Laser handicap that has them winning similar number of races to Solo or RS sailors, then the Laser mid fleet is comically advantaged... Their results seem to have the same sort of skewed distribution as other classes, except that the top end of the curve is truncated. Its weird.

I reckon for club racing you should set the handicap so its fairest for the maximum number of sailors of all abilities, even if that means a couple of guys at the top of the Laser fleet are apparently not getting results that match their ability. The guys doing the Sailjuice handicaps are trying to set numbers that are fair for the top boys in each fleet, and, I suspect, with a tendency so its the results of the top boys when the boat is in its conditions. The idea being that pretty much any class has a chance to win if the conditions are near its sweet spot. It means those of us with boats with polarised performance - and I'm not sure that my IC is actually any better than the Cherub in that respect - have less of an advantage when the conditions are great, but it also means someone like a Laser sailor is in with a chance if the conditions are reasonable for him/her and won't just be wiped out by a boat that hits perfect conditions.

In the long run I reckon it means that the distribution of prizes between different classes over the series will be more even, thus probably fairer. Its not something I'd be personally comfortable with, but it doesn't lack logic and it is thought out. Whether making the handicaps as fair as possible for potential winners whilst making them less equable for mid fleeters like me is the right thing to do, well, that's something that could be argued about forever, but to do what the Blaze people are doing and saying "waa, waa, mummy he did that its not fair", well that just makes them look bad to me. What these handicappers are doing is a valid experiemnt for a major series I think. It really does seem to be impossible, from what I've learned, to get a handicap that's fair for mid fleet and front of fleet at the same time.
« Last Edit: January 01, 2012, 05:24:09 PM by JimC »

Offline dean_ralph

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Re: The Bloody Mary
« Reply #24 on: January 01, 2012, 06:29:39 PM »
Just read through this thread, the rya list the cherub at 941 which i think the class know that this is a very biased number in the modern cherubs favour. I also sailed a 29er for a long time which is listed at 924, the 29er is slower around a course in a moderate winds than a cherub but will beat it in lighter winds (used this as comparison as its a boat i have experience with), I personally feel that the py requires adjusting, but this needs to be done in moderation taking into account all weather conditions not just its boat speed at one point of sail. Having an unfair py makes for ill feelings but this has to be considered in both cases too high or too low, could do with a bit of common sense and a bit of logic to be used.

Offline Andrew Whapshott

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Re: The Bloody Mary
« Reply #25 on: January 01, 2012, 09:50:52 PM »
Due to having no trailer,    I am now in SMOD mode for this event :(  See you all there.   

Offline phil_kirk

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Re: The Bloody Mary
« Reply #26 on: January 02, 2012, 02:02:54 PM »
there is a different aim for handicapping these big one off events (where the organisers appear to be trying to ensure the top of the fleet are correctly placed) and normal club racing. 

Interestingly Paul croote and Tim Unerman won a largeish club course at thornbury on new year's eve sailing off 890 in moderate conditions.  They were comfortably in front of the next non skiff boat and a couple of other reputable sailors from the club.  Therfore on that type of simple course there is room to drop the cherub handicap further. Thornbury have recently been doing there own analysis on handicaps and are setting different handicaps to those suggested by the rya.

Offline simon_jones

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Re: The Bloody Mary
« Reply #27 on: January 02, 2012, 05:24:43 PM »
Sadley still lacking a boat, so unable to go ourselves. However could be persauded to pull some strings for someone who
needs a crew.

Offline JimC

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Re: The Bloody Mary
« Reply #28 on: January 02, 2012, 07:43:35 PM »
Due to having no trailer,    I am now in SMOD mode for this event :(  See you all there.   
I have a Cherub sized trailer in Epsom: the cradle was made for a Bistro, although its been used for the Farr in recent years. I'm sure it could be made available...

Offline Graham Bridle

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Re: The Bloody Mary
« Reply #29 on: January 02, 2012, 08:45:31 PM »
Largely I concur with Jim on this subject, handicapping is impossible to get right, and bleating is definitely suicidal, especially when we don't have much data to fall back on. Lets just concentrate on keeping the boats looking good and in the public eye, and the faster people think we are the better, better than having the handicap raised and have people think we've got slower !

I think we did the sensible thing asking about it, and we got a response, now let the sailing do the talking.