Inter-class rating system

Rcsailing.net General Discussion
1

Any thoughts on an inter-class rating system?

I think there should be a way to race against any class, regardless of which class yacht you have. For example, a nirvana2 owner could race an IOM owner. I am picturing something like PHRF (rating system for big boats). As many of you know, PHRF has many problems, but every boat is different and there are so many different boats. There are only so many classes of RC yachts, which are governed under their own rules. This saves the time and effort of making a formula that applies to every boat. I think the rating should be seconds over one minute, instead of time over distance(PHRF). For example with time, a Marblehead would owe an IOM “X” seconds for every minute it took the Marblehead to finish the race. this seconds per minute would work in all wind conditions and course sizes. Being race committee would be a little more difficult, but a video camera and a spreadsheet with the formulas could make it almost just as easy. With this system, there are two kinds of starts. The easier of the two is a mass start, and then do the calculations at the end of the day. The second is more fair, the time of the race is estimated and the start times are calculated so that all the boats theoretically would be even, x seconds into the race. the second is more fair because the faster, larger boats aren’t ahead of, and covering the slower boats.
This may seem like it would be too complicated to run a regatta with this system, but with only two or three classes it seems manageable (think one meter regatta). Once everything is calculated, I am sure someone would be able to create software that does this automatically (similar to Sailwave).

Well, I have the rough idea, Now I need help refining it and calculating ratings.

2

I wish you well on this effort. I gave up on it about 3 years ago. The problem I ran into was (as example) the IOM Class secretary refused to provide the finishing times for first and last place boat at their national regattas so some kind of database could begin to be built. :rolleyes:

I’m familiar with Portsmouth (Time on time as you suggest) and the response was that it was too time consuming for anyone to time and record (only) two boats.

I also tried to interest the OPEN Class secretary at the time to consider the effort since all boats registerd in the Open Class pay the same dues, but never have an opportunity at a national regatta championship - one design or handicapped.

If a formal group was ever established under AMYA oversight, I would be happy to volunteer. I just was frustrated by the short-sightedness of established classes to help develop a method to allow non-class boats to race.

:mad:

I also might add I threwout for discussion the idea of a “Claiming Race” where a specific dollar limit on construction for one entry level class would be established. After the regatta series ANY competitor entered and participating could essentially “bid” on the winning boat. This would ensure the winner would receive at least (or at most) the established cost. Radio gear would be exempted and removed. The thought was the class would control the run-away expenses experienced in the IOM and Marblehead classes, and which seem to be an issue of concern by many new comers to r/c sailing/racing. If they knew going in the maximum they could spend was $500 and that they could purchase the winning boat for $500 at minimum (less radio) at the end of the yearly nationals, there would be less likelyhood of someone dumping an additional $300 into their personal boat to assure a win. That idea went down in flames too - and yet we still hear of new sailors who are buying the $100 Wal-Mart/eBay junk and then having to spend time and more money just to get them to sail - let alone being competitive. [sigh]

3

acquiring rough ratings shouldn’t be too hard, just get a few people together with different classes, run a lot of races and average the time differences per minute.
once some rough ratings are made, and a system is made for scoring, some people may become interested.

Your right about it being too difficult for the race committee. and I think I have a way to do it. have one person read off the sail number and time while another person writes it down. A way that everyone can race, is to set up a video camera on a tripod, looking down the line, and a timer in view of the camera. someone is needed to start the timer and call OCS’s. at the end of the day, the race committee looks through the tape and types the time of each boat into a excel document, which already has the boat info, and the corrected finish time is automatically calculated and the boats are sorted by finish time and that finish can be entered into a standard regatta scoring program.

I can make the excel document, i just need the ratings and to re familiarize myself with excel.

boats in the open class may need a formula to calculate their rating. the formula could be used to calculate the ratings of boats who are unsatisfied with their rating. I will assume that the formula, as well as class ratings will be constantly adjusted as the system is developed

4

Have you guys considered using a measurement formula somewhat similar to PHRF, only simplified? Maybe take into account LOA, LWL, beam, sail area, displacement and beam at waterline, modify the PHRF formula to deal with the simplified measurements, and turn this into a time-on-time rating. It may not be perfect, but it’s pretty close and much simpler than creating another formula from scratch. Even if, say, in a five-minute race a IOM gives 25 seconds to a Nirvana, and maybe that’s three or four seconds from being perfect either way, good skippering could still make the difference. And keep in mind that PHRF is faltering for the same reason that IRC and IMS are not popular anymore-the designers had time to design boats to the rule to take advantage of the measurement points-the huge tumblehome on IRC boats to increase waterline beam without increasing deck beam being a good example.

5

I suspect that even a very simple waterline, weight, beam and sail area would spawn some really ugly boats. I was hoping more for some kind of handicap similar to golf that self perpetuated the updates by using an average system over a series of races or regattas. Thus one hot (or dismal) night wouldn’t carry on throughout the year. It might play a part for a short period of time, but eventually the law of averages would override.

A simple method would be to base times by classes which consist of very few different boats. Boats continue to race as a one-design/developmental class. I.e. - no time differential for, say, the US1 Meter class. But add in the number of one meter sized boats and this task becomes daunting just due to the different models and their physical sailing abilities. As an example - how to rate a 1 meter Soling against an IOM. I wouldn’t even want to throw the multihull design into the mix - yet it is a legitimate design.

My idea for at least getting some data is to have a first and last place time for an IOM regatta - same for a US1M and an ODOM. Include the 1 Meter Soling and Seawind so you now have 5 major classes. A total of 10 times would be used (first and last) which gives the data for a total race time. Calculations can then be made as to how many minutes the slowest “CLASS” - not boat - would be given in order to tie the winning “CLASS” boat. Remember - we don’t do it by boat, but by class averages. This would still give the sailor with the fastest boat design a slight edge, but sailors with slower boats sailing better than their average would also see a reward for sailing better than average. It might take several multi-race regattas to get some good averages. If wind strength were included, it might provide a difference in rating depending on wind. Thus a mulithull in light air might get “killed” by a Seawind, might be middle of the pack after handicapping in medium air and would be fighting with an IOM in heavy air for the top spot. The only problem is sail area size changes as an IOM drops for “A” rig to “C” rig - but the Soling and ODOM are stuck with a one design single rig, regardless of wind strength.

With some of these minor issues set aside for a moment, using the average and handicap applied, one would start to see a pattern arising as times are computed to make all finishers times identical. Once these patterns are recorded and added to by multiple regattas and race committees, the eventual time average can be calculated and a handicap number assigned. The key is to get a large number of boats over a period of time so those averages emerge without a one-time hole-shot and hitting all the shifts skewing the average.

As noted this takes time to develop, and it requires participation by class race committees and secretaries. Without their support and timing and reporting, problems of geographical area handicaps like PHRF arise. Each year it isn’t done is one more year without a way to compare.

Since Portsmouth uses a class of boat with wind strength and actual time reporting, the one or two “custom” creations don’t have as big an impact. I was just frustrated that I couldn’t get folks to volunteer to provide even a few final times so I could develop a legitimate example to be used. We continue to speculate, and all we really need are the time differential and the approximate wind strength to begin to make this handicap idea work. What it is eventually called, or how the boats are rated cannot begin to be discussed unless we know that ON AVERAGE, an IOM finishes 4 minutes in front of a Soling 1 Meter. At least with honest data, one could proceed with some method.

I guess if everyone sails a one deign class with a minimum of 20 boats in the class (here in the US) they really could care less. Yet we decry the low turnouts and we already know there are many boats of only one or two in an area that would like to race together if there was some form of handicapping. Handicapping isn’t the best thing - but if it’s all you have then 5-6 different designs could at least sail together locally if nothing else.

Just some ramblings. Sorry

6

We did it a couple of different ways… one was the old “Name that tune…” method where you would say… I can give you XX seconds and still beat you… and the other would accept or decline.

The other was if you had a LOT of guys with different boats… was to split into two teams and half race at a time while the other half would “bet” on those racing, the winning team having the most chips/matches whatever at the end. The betting was simple. The non-racing group would “handicap” the races and give odds. I say that this beats that by this many seconds… and I give 3-1 The racing group is on the water doing there thing, and the guys on shore are betting on the outcome.

The third way was if you were willing to swap transmitters, you could do that old aggragate deal where you sail each one of the boats once and take the total time.

Another was I offer this boat +XX seconds against that boat…and then let the other person chose which boat he wants to sail… this is about the BEST way of getting a fair handicap because the guy handicapping is going to try and cut it as perfect as possible because if it is lopsided… the other guy gets to pick the obvious winner.

:zbeer:

7

I think switching boats is the easiest thing for people. I would do this myself but all I have is a nirvana2 and a few boats under construction and I haven’t found anyone in the area who sails rc (yet). all you need to do this is:

  1. a friend with a different class boat, and is willing to swap boats for a few races.
  2. a timer, a watch will do
  3. a piece of paper and a pencil
  4. a course

run a few races, writing down the finish times and be sure to start the timer at “go”. then switch boats and do the same thing. If a lot of people did this and sent me the info, I could do all the math and get some rough ratings for those boats. if more than two people are involved, be sure everyone sails each boat and distinguish who sailed it in which races. If you send in information often, your ratings will become more accurate. you can e-mail me your results at eric.schwarm@gmail.com. or you could just video tape the races and send them to me, but be sure everyone sails each boat the same number of races.

a rating for an open class boat can be done this way by racing a class boat. this is also an opportunity for those 1/10 scale boats to get in on the racing, and once they have a rating, they can race fairly against each other.

Dick, the issue about the wind strength shouldn’t cause too many problems, if you determine your rating in average conditions of your area, the ratings should work well for you. and if not, i am sure that giving you different ratings for different conditions wouldn’t be a problem.

using a formula would only create a huge mess, with no useful outcome. and it requires a ton of hard thinking and a lot of time to come up with a formula which works for 3 classes never mind all of them or the open class.

8

Historically, most handicapping systems (which, BTW, is the way rating rules started out, way back when) have a limited life. The generally work until people start designing new boats to them.

A simple way to enforce handicapping is to do endurance race scoring. Boats race for a fixed amount of time. At the end of the time period boats finish the lap they are on and then retire. Scoring is based on the number of laps a boat completes; boats that complete the same number of laps are scored in the order they finished their last lap. That is, if A and B are both on lap 10 when the ending signal is given, and B crosses the finish line ahead of A, then B is scored ahead of A.

Handicap allowances can be introduced by giving boats deemed to be slower more time, and modifying the scoring rule given above. The modification is that the scorer records the time of day that each boat crosses the finish line, to resolve cases where two boats of with different time allowances complete the same number of laps.

Let’s say A has no time allowance and B has a time allowance of 15 minutes. Race is sailed for (say) 2 hours. Boat A gets the “last lap” call at 2:00 and finishes her lap 10 at 2:25; boat B gets “last lap” call at 2:15 and finishes her lap 10 at 2:30. B (9 completed laps at end call plus 15 minutes to finish lap 10) then beats A (9 completed laps to end call plus 25 minutes to finish lap 10). This method of scoring is cruder than a true time-on-time or time-on-distance because no allowance is applied to the time required to finish a boats last lap.

On the other hand, it is much easier to score, avoids the confusion of staggered starts, and, since the number of laps and elapsed time of each boat is recorded for each race, a record of performance exists which can be used to recompute time allowances.

Cheers,

Earl

9

Thanks for the explanation Earl.

I need to clarify my original posts, in that I subscribe to time-on-time handicaps.

Since it is difficult to verify accuracy of course distance, and since each club might have a longer or shorter course, the time-on-time doesn’t need to know distance traveled - only the total time it took to sail from start to finish. If there are multiple starts at 5 minute intervals, they “could” be combined at the end with a +5, +10 or +15 to equate to later starts from heat/race #1. Doing this means watching wind and water conditions so later fleets are racing in similar conditions as the earlier fleets.