RYA NHC - Could sandbagging be grounds for protest?

[flaming]

If PY isn't about who's sailing the boat closest to its maximum then it's entirely fair to describe it as "not serious" as put simply that is exactly what racing is.

I'm massively in favour of anything that gets more people racing. If PY, or whatever, encourage more people to try racing, then great.

My point is that if you want to discover who the best crew is, and you insist in doing this in dissimilar boats, then a handicap system that measures only the boat has to be the only way.

The debate about falling fleet numbers is more complicated in my opinion.

 

[Piddy]

Well thats wrong mathematically. I was told by the guy that did the work that the model used to calculate the NHC numbers was very similar to the IRC model and the data used was sales brochure data from the boat manufacturers etc.

If you take your formula and apply it to the handful of boats that had primary and therefore very well established PY benchmarks, you get the numbers in column C which are 16% higher than the correct NHC numbers:


[TABLE="class: grid, width: 500, align: center"]
[TR]
[TD][/TD]
[TD]A[/TD]
[TD]B[/TD]
[TD]C[/TD]
[TD]C as% B[/TD]
[TD]D[/TD]
[TD]D as % A[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]primary[/TD]
[TD][/TD]
[TD]PY converted[/TD]
[TD][/TD]
[TD]nhc converted[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]py no[/TD]
[TD]nhc no[/TD]
[TD]1/py*1000[/TD]
[TD][/TD]
[TD]using irc formula[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]sigma 33[/TD]
[TD]929[/TD]
[TD].909[/TD]
[TD]1.076[/TD]
[TD]118%[/TD]
[TD]952[/TD]
[TD]102%[/TD]
[/TR]
[TR]
[TD]impala[/TD]
[TD]965[/TD]
[TD].892[/TD]
[TD]1.036[/TD]
[TD]116%[/TD]
[TD]973[/TD]
[TD]101%[/TD]
[/TR]
[TR]
[TD]achilles 24[/TD]
[TD]1079[/TD]
[TD].843[/TD]
[TD].927[/TD]
[TD]110%[/TD]
[TD]1041[/TD]
[TD]96%[/TD]
[/TR]
[TR]
[TD]hunter 707[/TD]
[TD]928[/TD]
[TD].937[/TD]
[TD]1.078[/TD]
[TD]115%[/TD]
[TD]918[/TD]
[TD]99%[/TD]
[/TR]
[TR]
[TD]sonata[/TD]
[TD]1039[/TD]
[TD].831[/TD]
[TD].962[/TD]
[TD]116%[/TD]
[TD]1059[/TD]
[TD]102%[/TD]
[/TR]
[TR]
[TD]J24[/TD]
[TD]935[/TD]
[TD].905[/TD]
[TD]1.070[/TD]
[TD]118%[/TD]
[TD]957[/TD]
[TD]102%[/TD]
[/TR]
[TR]
[TD]average[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]116%[/TD]
[TD][/TD]
[TD]101%[/TD]
[/TR]
[/TABLE]


Obviously that will leave your club members happier - after all we all know that we lose races because our boat cannot possibly be sailed to its handicap unlike every body else's boat. Certainly thats my problem. But its really a bit of self deception and it wont help anyone to beat that Sigma 33 hot shot.

There is a well established and well correlated formula for converting IRC numbers into PY trial numbers . It is PY = 850*(IRC no) ^-1.187. Now given the source of the NHC numbers I have tried using this formula to convert NHC numbers into PY to see how close they are. The results are shown in column D . I apologise that I have converted NHC into PY but I just coulnt get my useless brain round using the formula in reverse to convert primary PY to NHC. Never mind, the numbers show this conversion formula is within 1% of the primary PY numbers with the exception of one very old boat which for some reason is 4% adrift. Bit better than 16% isnt it?

In the end your club can do whatever it wants for internal races, but I realkly dont see the point in creating your own false NHC numbers rather than just continuing with PY as you currently run it . After all you wont be able to use your made up NHC numbers in any open competition or at any other club will you?

I think your table shows our problem...

If you compare the (old) PY of the Sigma and the Achilles it shows a difference of 150 giving a performance difference of 15% (150 seconds in 1000).
When you look at the NHC derived PY numbers the difference is now only 89. Why would the Achilles owner be happy to accept a rating cut of over 6% to the Sigma? Is he suddenly able to sail 6% faster this season? In reality, the Achilles owner won't come out to play. Even by ignoring the established conversion of IRC and just using the reverse of my PY formula on the new NHC number, the Achilles comes out similarly worse off.

The changes have an adverse affect on older designs or those not designed to fit a racing formula - and that describes most but not all of the boats we have in our fleet. We're looking to promote the beneficial effects of this new system without ruining the chances of most of our regular racers - which is what would happen if we just implement the NHC system with the RYA base numbers. In our case we believe it would have two effects; The few performance boats we have would walk away with all the trophies and our regular racers in older cruising boats would give up racing - not what we want nor I suspect, what the RYA wants.

As I have said a number of times, our racers are racing older, cruising orientated boats and are very unlikely to want to race elsewhere - those that are keen enough (and with appropriate boats) would accept our artificial world and then go off and race competitively with a different handicap.

 

[Bosun Higgs]

I think your table shows our problem...

If you compare the (old) PY of the Sigma and the Achilles it shows a difference of 150 giving a performance difference of 15% (150 seconds in 1000).
When you look at the NHC derived PY numbers the difference is now only 89. Why would the Achilles owner be happy to accept a rating cut of over 6% to the Sigma? Is he suddenly able to sail 6% faster this season? In reality, the Achilles owner won't come out to play. Even by ignoring the established conversion of IRC and just using the reverse of my PY formula on the new NHC number, the Achilles comes out similarly worse off.

The changes have an adverse affect on older designs or those not designed to fit a racing formula - and that describes most but not all of the boats we have in our fleet. We're looking to promote the beneficial effects of this new system without ruining the chances of most of our regular racers - which is what would happen if we just implement the NHC system with the RYA base numbers. In our case we believe it would have two effects; The few performance boats we have would walk away with all the trophies and our regular racers in older cruising boats would give up racing - not what we want nor I suspect, what the RYA wants.

As I have said a number of times, our racers are racing older, cruising orientated boats and are very unlikely to want to race elsewhere - those that are keen enough (and with appropriate boats) would accept our artificial world and then go off and race competitively with a different handicap.

Our fleet make up is similar though we dont have an Achilles in it. But you are ignoring that both the old PY and the new NHC are progressive handicaps and the numbers in the list are only starters with fairly rapid adjustment race to race to reflect actual performance thereafter. For example we have two sigma 33s in our fleet, one racing off 1009 and one off 937, both with chances of winning. One has a good crew and the other are learning - we hope. Thats why there is no starting adjustment for twin keels or o/b versus inboard or spinny or small headsail ( my problem). If you were doing that race to race adjustment using PY then the new handicap will very quickly get you in the same place -

What I dont understand is why you have chosen to convert using the formula you have done since it gives results that are wildly out compared with the old PY numbers. You wont be allowed to use those numbers at other clubs or for open events. So why dont you just continue with your established PY numbers anyway? Not trying to be rude but I wonder if that reflects the maths skills of your race committee?

 

[Bosun Higgs]

My point is that if you want to discover who the best crew is, and you insist in doing this in dissimilar boats, then a handicap system that measures only the boat has to be the only way. .

You had it right in an earlier post. The only way to do what you describe is in one class racing. IRC doesnt work in tidal waters any more than any other handicap system. Our IRC fleet varies from 0.939 to 1.056 which is near enough 10% and with tides of 3kn springs, the faster boats have a 20% advantage uptide not 10 and 6% downtide.

In many ways PY gives a very good indication of who is the better crew. Just look at the end of series handicap compared with the trial number and you'll see who sails well. The two sigmas I mentioned above are a case in point.

But its all academic really. We do it for fun and bragging rights in the bar afterwards. You chose the sort of racing you want to do.

 

[Piddy]

Our fleet make up is similar though we dont have an Achilles in it. But you are ignoring that both the old PY and the new NHC are progressive handicaps and the numbers in the list are only starters with fairly rapid adjustment race to race to reflect actual performance thereafter. For example we have two sigma 33s in our fleet, one racing off 1009 and one off 937, both with chances of winning. One has a good crew and the other are learning - we hope. Thats why there is no starting adjustment for twin keels or o/b versus inboard or spinny or small headsail ( my problem). If you were doing that race to race adjustment using PY then the new handicap will very quickly get you in the same place -

What I dont understand is why you have chosen to convert using the formula you have done since it gives results that are wildly out compared with the old PY numbers. You wont be allowed to use those numbers at other clubs or for open events. So why dont you just continue with your established PY numbers anyway? Not trying to be rude but I wonder if that reflects the maths skills of your race committee?

No offense taken - it's my maths.
My understanding of PY is that:
CT = ET x (1000/PY)

if so (1000/PY) is simply making the PY number into a TCF.
My badly phrased (1/PY)*1000 gives the same figure, meaning we will be using our existing handicaps to start a progressive system rather than a set of numbers that in our case suit the couple of racing boats we have in our fleet. The numbers only adjust rapidly when you sail a lot of races. We only have 25 boats registered to race in our fleet and they only individually race sporadically so it might take 2 seasons to adjust a handicap back to the relative level they currently are. Hardly a way to keep our existing racers enthusiastic!

I'm not sure why you think they are wildly out when they are just the PY numbers we have used for years. Perhaps I have missed something!
I'm not sure that any numbers are transferable between clubs/events so no change and as I said before there aren't many of our 'racers' that are likely to do so.

Of course One design racing is the best but we don't have that luxury and this is the best way we can see of using the new NHC system.

 

[Tim Jeffery]

Absolutely agree with flaming - and have you read the calculation methods for NHC - Crikey! This system is a nightmare and exactly why I will now only sail IRC.

Nothing more annoying than sailing a stormer in a well prepared boat with a great crew and being beaten by a boat on a bandit handicap. If you do not sail well and that includes having a well prepared boat and crew then you should not expect to do anything but make up the numbers at the back.

That is how the rest of life works.

So it is IRC or single class - NHC is mickey mouse.