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Rupert View Drop Down
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Topic: New class PY numbers?
    Posted: 19 Feb 17 at 9:01am
Via a multiple of 1.2 and 9.46. between the 2, the handicap had gone to 124. Old and new numbers simply tell you about relationships between boats, not which he has moved which way.

The RYA gave up on a boat to put things round. Maybe finding out why would be a good idea before reinventing the square wheel.
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Sam.Spoons View Drop Down
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Posts: 3401 		Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 10:30pm
Yes, once upon a time but it's now on 1163........ And, in real life they must have got faster not slower.....
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Posts: 1345 		Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 10:12pm
Originally posted by Sam.Spoons

Originally posted by RS400atC

To get back to th OP, most new classes are comparable to several existing classes. If you come up with a 2 person hiking boat, about 14 ft long, sym kite I'd look at the weight, sail area, sophisticated rig or not, then have a guess at where it slots in between a Merlin and a GP14. Or maybe Skipper 14 to Bosun spectrum?
Likewise if you are talking one man, one sail, just look at all the others of the same concept and similar size.

If you want to pluck a PY for the spice out of thin air, don't look at catamarans, toppers or Merlins.
Look at the int 14 and see how many excuses it's got to be slower. Look at the L4k and the 3k. Maybe the B14. Don't look at things with grossly diffferent length, weight, righting power or sail area, Don't even think about thinking about boats with different basic rig concept.

But at the end of the day, there are still going to be boats which don't deliver what their outline spec suggests they should.
Just as there have been designs of Merlin which never went anywhere, there have been many boats which are simply not very fast despite lots of righting power and sail area, even if you make allowance for things like beam at the waterline which makes a sensible boat for beginners.
Then you've got to allow for class rules which restrict performance, like some of the nastier SMOD sails or limitations on sheeeting angles etc. Or maybe the other extreme of boats with raking rigs etc.

A good post RS, thanks. That seems the most sensible way (and I assume that's how it's done) but no one person/committee makes the decision. In some cases I guess it's the designer, others the manufacturer/marketing guys and yet others the hosting clubs racing manager. Those with axes to grind will recommend a number that makes the boat either seem faster or one that makes it more competitive depending on the boat and their aspirations for it. 

I do like GRFs suggestion that there should be a 'scratch' boat that remains on 1000 while the others move around it, that way all those lost classes that haven't had a real PN for years will, in theory, have a fixed reference point but even the L@ser will have got a little faster over the years, particularly with the Mk2 sail and new carbon topmast so even that is doomed to failure Unhappy

Wasn't that the Firefly at 100?
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Rupert View Drop Down
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 9:25pm
Sail area approx the same as the ISO? Hull length the same as a Buzz? For your purposes, taking an average would probably be as accurate as any other guess until you can crack the boat handling to the point where results are near average potential. Or hand it over to a tame racing driver and see how it does then? Which is roughly what Dougal is suggesting for all new boats. Quick snapshot to tide everyone over until the numbers stack up.
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Sam.Spoons View Drop Down
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Posts: 3401 		Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 8:47pm
An idea of how many points (or better %) difference and extra trap or 20% more sail area made (or adding/removing the kite) would be useful then.

Buzz is identical to Spice apart from one extra wire and +50% (roughly) sail area. Any other differences are cosmetic. 

At least that would give race officers something to go off and get those lost classes racing.
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Rupert View Drop Down
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 7:31pm
I guess you could have a meeting of 90s asymmetric dinghies to set relative handicaps, then move them all as one when any one of them gets enough returns to be statistically valid so they match the rest of the system. Would any get enough returns, though?
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RS400atC View Drop Down
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Posts: 3011 		Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 6:58pm
Originally posted by Rupert

For the Spice, all you have to do is decide how much difference a bigger rig and extra wire makes over the Buzz. Can't be more than 30 or 40 points, can it? Still the same flat, tea tray hull, same length, similar weight.

Only if you think the Buzz PY is right to start with!
And there's a lot more righting power and a fair bit more sail area.
But it would be a reasonable starting point, provided you were going to race it against Buzzes.
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Dougaldog View Drop Down
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Posts: 356 		Post Options Post Options   Quote Dougaldog Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 6:58pm
Good point Rupert. But in a way - that is just what I'm saying. If you had an accepted number for the Buzz (based on real data) and then you wanted to launch the Spice, you ran it over the pre determined course for a day or so, downloaded the tracking data, compared it to the and then you can make an informed decision. Rather than the wet finger in the wind, is it 30 points or 40 (or 20 or 50 even) you've data, fully in the public domain, that everyone can see.
RS 400 also makes a good point. You're going to have to compare apples with apples. It isn't difficult to set a bench mark for a genre, all the more so when it is a SMOD, a boat that once it has an established number, it is hard to explain why the PY is changing (unless there has been a change in the equipment used). In the end - it isn't rocket science  - but what would we have to complain about then. I'm sure the man of kent will come up with something!
Dougal H
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Sam.Spoons View Drop Down
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Posts: 3401 		Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 6:53pm
Originally posted by RS400atC

To get back to th OP, most new classes are comparable to several existing classes. If you come up with a 2 person hiking boat, about 14 ft long, sym kite I'd look at the weight, sail area, sophisticated rig or not, then have a guess at where it slots in between a Merlin and a GP14. Or maybe Skipper 14 to Bosun spectrum?
Likewise if you are talking one man, one sail, just look at all the others of the same concept and similar size.

If you want to pluck a PY for the spice out of thin air, don't look at catamarans, toppers or Merlins.
Look at the int 14 and see how many excuses it's got to be slower. Look at the L4k and the 3k. Maybe the B14. Don't look at things with grossly diffferent length, weight, righting power or sail area, Don't even think about thinking about boats with different basic rig concept.

But at the end of the day, there are still going to be boats which don't deliver what their outline spec suggests they should.
Just as there have been designs of Merlin which never went anywhere, there have been many boats which are simply not very fast despite lots of righting power and sail area, even if you make allowance for things like beam at the waterline which makes a sensible boat for beginners.
Then you've got to allow for class rules which restrict performance, like some of the nastier SMOD sails or limitations on sheeeting angles etc. Or maybe the other extreme of boats with raking rigs etc.

A good post RS, thanks. That seems the most sensible way (and I assume that's how it's done) but no one person/committee makes the decision. In some cases I guess it's the designer, others the manufacturer/marketing guys and yet others the hosting clubs racing manager. Those with axes to grind will recommend a number that makes the boat either seem faster or one that makes it more competitive depending on the boat and their aspirations for it. 

I do like GRFs suggestion that there should be a 'scratch' boat that remains on 1000 while the others move around it, that way all those lost classes that haven't had a real PN for years will, in theory, have a fixed reference point but even the L@ser will have got a little faster over the years, particularly with the Mk2 sail and new carbon topmast so even that is doomed to failure Unhappy
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transient View Drop Down
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Posts: 715 		Post Options Post Options   Quote transient Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 17 at 6:52pm
Originally posted by RS400atC

2k looks pretty dog-like on the sea most of the time.

Chortle, seperate discussion needed there about differing hull weights within a class (except that it's already been discussed to death).


But there is a point there, that asy boats like the 2k don't work on PY against Ents or Merlins or GP14s, because the boats are disparate.
Likewise racing the 400 against say Scorpions, we will lap them if the wind and course suit us, other days we can't shake them off.
An RS400 on a triangle course where our kite is just right needs a different PY from on a square course where we can't carry the kite on the reaches and have to do 40% extra distance on the run.
If people stopped trying to use PY outside the bounds where it can work, the numbers might have a chance of making sense.

yep. triangular courses where an assy can fly a kite for 66% + of the course and a symm for sometimes 0%




Edited by transient - 18 Feb 17 at 6:52pm
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