Rafael wrote: > I was going to try to use the hull speed as criteria, but since it only > takes the length and not the width (at waterline level), a wide long boat > will be slower than a narrow rounded bottom boat. > > > > Is there some rule of thumb to take length and width and try a simple > equation that will give some kind of handicap? I don`t think there would > be > time to make hull measurements before the race to run the drag programs. Unfortunately the answer is no. No matter what simple formula you use it will be unfairly punitive to some and unfairly beneficial to others. Resistance is just to complex. I can give you a lot of reasons why mathematical handicapping is flawed. I would not even trust my own resistance formula (KAPER - used by Sea Kayaker to evaluate boats) which is less than reliable for many boats and worse if one tries to modify it. I have seen a number of methods used to equalize casual racing. One type has everyone start out racing to a marker buoy. When the first boat reaches it he turns around for the return leg. Then as he approaches following boats they turn around. This assumes that the competitors will not cheat and paddle slowly for the first part of the race. It seems to work where everyone is just having fun and not absorbed with winning ands usually results in a whole lot of boats finishing at one time which is a lot of fun. For serious racers we sometimes used a "claiming race" strategy. Each competitor was free to pick what he thought was a fair handicap which had a boat price attached to it. The higher the handicap the lower the price (i.e. the slower you think your boat is the lower your selling price). If he/she won they had to put their boat up for sale for the price affixed to their boat. This kept the racing guys from using too low a handicap and risking losing their boat for too low a price. It is truly amazing how much higher the handicaps got when this system was used. :-) This is also done in horse racing I think Another method is to have two races of shorter duration that are used to establish a handicap of which one is the actual race and the other for establishing the handicap. The key is not to tell the competitors which race was the actual race and which is for handicap purposes. This forces the competitors to try hard in both races since they won't know which is the real race. Anyone trying to cheat will be obvious. The handicap is calculated from the handicap race. People will rarely finish in the same order in both races so it lends a bit of uncertainty to the racing. I think it works best if there is a day or two between the races and would probably benefit from more than two races to give you two races to average for the handicap. There are probably other methods but these have worked in the past although last one is a bit extreme. I once saw a paddler slow down to finish second because he thought he had priced his boat too low. Cheers John Winters *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
On Wed, May 21, 2008 at 4:17 AM, John Winters <jdwinters_at_eastlink.ca> wrote: > > Unfortunately the answer is no. No matter what simple formula you use it > will be unfairly punitive to some and unfairly beneficial to others. > Resistance is just to complex. Not only that, but if you do come up with a formula and if the races are important enough to the racers, someone will design boats that use loopholes in that formula to gain an advantage. In the 1970s the IOR produced bizarre hull shapes that were only useful if the boat raced to that rule (which is no longer in style). And a boat design (or designer) that successfully finds a rating loophole can become more in demand and therefore more valuable. Your post described some interesting rating systems that I've never heard of but the common thread in rating systems seems to be that, just as you say, no matter what you use someone will gain and someone will lose; and a lot of them will cheat. It seems that you can't fool human nature. Thanks for those illustrations. I particularly liked the one where the leader who rounds the mark first discovers that everyone who was behind is now in front. Talk about a dis-incentive to be first to the mark. Craig *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
Ok, I did try some equation. I took something like 20 pieces of data that Matt Broze has in his spreadsheet for different kayaks, picking up both very short and wide and very long and narrow and many in between, and using the 5 pound drag, I plotted the calculated speed vs the LWL/BWL (length on waterline vs beam on waterline). A couple of points were off the trend but a trend could be seen, so I made a linear regression and found the statistical straight line that best describes the speed versus l/b. Then I found out the catalog length and beam and plotted them also obtaining similar results. The only problem is that the correlation factor was about 0.73 for both cases, which gives a very large error margin for one specific competitor, and therefore big injustice could be made using that approach. I agree then, that the simplistic approach will not work. Right now, injustice is larger because all boats compete at the same time, but nobody can argue the results. Your time is your time and that's it. So I guess the next best thing is to separate the groups according to the simple rule suggested by the soundrowers organization. Thanks a lot to everybody for their input. It was very educational. Best Regards, Rafael. -----Mensaje original----- De: owner-paddlewise_at_paddlewise.net [mailto:owner-paddlewise_at_paddlewise.net] En nombre de Craig Jungers Enviado el: jueves, 22 de mayo de 2008 11:01 Para: John Winters CC: PaddleWise_at_paddlewise.net Asunto: Re: [Paddlewise] hull speed On Wed, May 21, 2008 at 4:17 AM, John Winters <jdwinters_at_eastlink.ca> wrote: > > Unfortunately the answer is no. No matter what simple formula you use it > will be unfairly punitive to some and unfairly beneficial to others. > Resistance is just to complex. Not only that, but if you do come up with a formula and if the races are important enough to the racers, someone will design boats that use loopholes in that formula to gain an advantage. In the 1970s the IOR produced bizarre hull shapes that were only useful if the boat raced to that rule (which is no longer in style). And a boat design (or designer) that successfully finds a rating loophole can become more in demand and therefore more valuable. Your post described some interesting rating systems that I've never heard of but the common thread in rating systems seems to be that, just as you say, no matter what you use someone will gain and someone will lose; and a lot of them will cheat. It seems that you can't fool human nature. Thanks for those illustrations. I particularly liked the one where the leader who rounds the mark first discovers that everyone who was behind is now in front. Talk about a dis-incentive to be first to the mark. Craig No virus found in this incoming message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.24.0/1460 - Release Date: 22/05/2008 7:06 No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.24.0/1460 - Release Date: 22/05/2008 7:06 *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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