Possible anomaly in scoring?

I’ve just scored an RS Aero event, and as some may know they like their results presented in both individual classes and handicap overall. So I set up each boat under the individual subclass, with a fleet of Aero 5/7 etc, and created an alias for every competitor, and put the Aliases all in fleet “Aero Overall”. Set up the scoring system for places for each fleet, and PY for the overall, and record times. So far so good.

However we also “Grand Prix finish” stragglers, so there may be boats that sail a lap or more fewer than the leaders. Sailwave calculates a corrected time for the boats that do one lap fewer and scores them like that. Now here, I think is a possible anomaly. I imagine those here are mostly familiar with the possibility that someone who passes the finish just before the S flag goes up and has a very slow last lap may correct out just behind someone who did one lap less, and really that is unfortunate but inherent in average lap handicap racing. However with the way Sailwave appears to be handling the grand prix finishes this would seem to also be a possibility when the class is scored on finishing position, and that seems highly undesirable.

Is this behaviour by design? It is, I suppose, easy enough to work round by say adding an hour to the elapsed times of the stragglers, but it does feel as if the results are being calculated more by time than by place.

Jim C, Island Barn RSC

Hi Jim,

The “slow last lap” is definitely not dealt with by Sailwave, that has been the topic of a previous discussion.

For your scenario we usually use prize groups rather than aliases. Set up a prize group for each rig and score as a single Average Lap Time race then the prize groups will automatically pull out the rig places for you.

Ian

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On 20 Mar 2018, at 10:58 pm, yho@devboats.co.uk [sailwave] sailwave@yahoogroups.com wrote:

I’ve just scored an RS Aero event, and as some may know they like their results presented in both individual classes and handicap overall. So I set up each boat under the individual subclass, with a fleet of Aero 5/7 etc, and created an alias for every competitor, and put the Aliases all in fleet “Aero Overall”. Set up the scoring system for places for each fleet, and PY for the overall, and record times. So far so good.

However we also “Grand Prix finish” stragglers, so there may be boats that sail a lap or more fewer than the leaders. Sailwave calculates a corrected time for the boats that do one lap fewer and scores them like that. Now here, I think is a possible anomaly. I imagine those here are mostly familiar with the possibility that someone who passes the finish just before the S flag goes up and has a very slow last lap may correct out just behind someone who did one lap less, and
really that is unfortunate but inherent in average lap handicap racing. However with the way Sailwave appears to be handling the grand prix finishes this would seem to also be a possibility when the class is scored on finishing position, and that seems highly undesirable.

Is this behaviour by design? It is, I suppose, easy enough to work round by say adding an hour to the elapsed times of the stragglers, but it does feel as if the results are being calculated more by time than by place.

Jim C, Island Barn RSC

Hi Jim,
Your Idea of using Aliases is fine but I don’t understand exactly what you have done as you seem to infer if you have some with time and some with places. Perhaps you could share your blw file.

Ian’s idea of prize groups is also fine but you will just have to score twice with a different “score by”

As Ian mentions there is a discussion on the slow last lap a few years ago on the forum but I don’t think that is what you are asking about. Perhaps you could confirm.

Jon

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On 21 March 2018 at 05:52, Ian Bullock ian_bullock@me.com [sailwave] sailwave@yahoogroups.com wrote:

Hi Jim,

The “slow last lap” is definitely not dealt with by Sailwave, that has been the topic of a previous discussion.

For your scenario we usually use prize groups rather than aliases. Set up a prize group for each rig and score as a single Average Lap Time race then the prize groups will automatically pull out the rig places for you.

Ian

On 20 Mar 2018, at 10:58 pm, yho@devboats.co.uk [sailwave] sailwave@yahoogroups.com wrote:

I’ve just scored an RS Aero event, and as some may know they like their results presented in both individual classes and handicap overall. So I set up each boat under the individual subclass, with a fleet of Aero 5/7 etc, and created an alias for every competitor, and put the Aliases all in fleet “Aero Overall”. Set up the scoring system for places for each fleet, and PY for the overall, and record times. So far so good.

However we also “Grand Prix finish” stragglers, so there may be boats that sail a lap or more fewer than the leaders. Sailwave calculates a corrected time for the boats that do one lap fewer and scores them like that. Now here, I think is a possible anomaly. I imagine those here are mostly familiar with the possibility that someone who passes the finish just before the S flag goes up and has a very slow last lap may correct out just behind someone who did one lap less, and
really that is unfortunate but inherent in average lap handicap racing. However with the way Sailwave appears to be handling the grand prix finishes this would seem to also be a possibility when the class is scored on finishing position, and that seems highly undesirable.

Is this behaviour by design? It is, I suppose, easy enough to work round by say adding an hour to the elapsed times of the stragglers, but it does feel as if the results are being calculated more by time than by place.

Jim C, Island Barn RSC

Jon Eskdale

03333 443377

07530 112233

—In sailwave@yahoogroups.com, <ian_bullock@…> wrote :

The “slow last lap” is definitely not dealt with by Sailwave, that has been the topic of a previous discussion.

In handicap average lap racing that’s the right thing to do, since if you were to attempt to juggle two boats of the same class what would you do about two boats of different classes with the same handicap, and then two different classes with different but very close handicaps.

But when the race is being scored without handicaps its surely incorrect to average lap. It means that you have to record places rather than finishing times, which may not be convenient and involve double entry. Its also why I prefer to use aliases rather than extract results. It is possible for the results in a fleet scored on places to be in a different order to the results for the same boats scored on average lap handicaps. Neither is wrong, they are just different scoring systems.

Jim C

OK, I’ve uploaded jimcaeroexample, which has had one time changed from what really happened to show the thing that worries me.

Fleet RS Aero Overall has rating system RYA Portsmouth, and fleet RS Aero 7 has rating system none

We are only concerned with Race 1.

In Race 1 1747 sails 3 laps for elapsed time 29:15, and 1566 sails 4 laps for elapsed time 39:05.

Firstly the RS Aero Overall result for Race 1.

Under Portsmouth Yardstick in my opinion 1747 is correctly scored 4th, with CT 0:36:31, and 1566 5th with CT 0:36:36.This is the slow last lap artifact that is inherent in average lap scoring. Some folk may not like it, but its the nature of the beast.

In Fleet RS Aero 7 the rating system is none. This means, I submit, that average lapping should not be in use, because it does nothing useful when boats are scored strictly on elapsed time. But because the system is calculating an average lap, 1747 is given CT 0:39:00, just ahead of 1566.

Because the elapsed times are required for the Aero overall result its not possible to work round the issue by simply recording places.

Jim C

Hi Jim,

Thanks for the file.

Looking at the first case - Race 1 and the competitors 1566 and 1747.

As you correctly say this is a case of the slow last lap syndrome.

If you look back to around 21st Jun 2016 this was discussed in the forum.

There is a document I believe RYA that states:-

If a boat ends with a corrected time greater than a boat which completed less laps but has the same

PN a modifying calculation should be applied as follows:

Modified time = Corrected time x multiplier

Multiplier = (slowest x (fastest laps–1)) / (about to finish time x fastest laps)

Where:

Fastest Laps is Actual Laps completed by the fastest boat in the group. Slowest is the Elapsed Time of

the slowest boat in the group.

NB this is only applied to a group of boats with the same PN where one or more have been effected

by sailing differing number of laps and the corrected times do not reflect a fair outcome.

The big problem here is to implement this, as I see it you would have to enter the lap time for every boat because you don’t know which boats are going to be affected until you score the series. This would be a big load on the race team recording all the lap times of all the boats and then the scorer to enter them all and then major changes to Sailwave to handle it.
I’m not saying I wouldn’t implement it but would people record every lap time for every boat and enter them into Sailwave?

For the second case - I understand what you are trying to do but I’m afraid that will not work because there are no places entered for those competitors only times and as you have entered the number of laps Sailwave will then automatically switch to average lap. In the file you supplied the RS Aero Overall as actually set to PY and not to none but it wouldn’t make any difference due to the reasons I’ve just given

Jon


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On 21 March 2018 at 20:36, yho@devboats.co.uk [sailwave] sailwave@yahoogroups.com wrote:

OK, I’ve uploaded jimcaeroexample, which has had one time changed from what really happened to show the thing that worries me.

Fleet RS Aero Overall has rating system RYA Portsmouth, and fleet RS Aero 7 has rating system none

We are only concerned with Race 1.

In Race 1 1747 sails 3 laps for elapsed time 29:15, and 1566 sails 4 laps for elapsed time 39:05.

Firstly the RS Aero Overall result for Race 1.

Under Portsmouth Yardstick in my opinion 1747 is correctly scored 4th, with CT 0:36:31, and 1566 5th with CT 0:36:36.This is the slow last lap artifact that is inherent in average lap scoring. Some folk may not like it, but its the nature of the beast.

In Fleet RS Aero 7 the rating system is none. This means, I submit, that average lapping should not be in use, because it does nothing useful when boats are scored strictly on elapsed time. But because the system is calculating an average lap, 1747 is given CT 0:39:00, just ahead of 1566.

Because the elapsed times are required for the Aero overall result its not possible to work round the issue by simply recording places.

Jim C

Jon Eskdale
07530 112233

Skype “eskdale”

OK thanks Jon,

As you say, not the place to discuss the slow last lap problem/feature/artifact.

However I do submit that the use of average lap timing/scoring when there are no handicaps in use is simply incorrect.

regards, Jim C

Hi Jim - on the topic of no average lap timing when rating system is set to none. If you set the rating system to none. Sailwave will not apply any handicap ratings it will use elapsed time. But if you specify laps that are different for different competitors then it will use average lap timing as it has no other way of doing it.
Jon

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On 22 March 2018 at 09:41, yho@devboats.co.uk [sailwave] sailwave@yahoogroups.com wrote:

OK thanks Jon,

As you say, not the place to discuss the slow last lap problem/feature/artifact.

However I do submit that the use of average lap timing/scoring when there are no handicaps in use is simply incorrect.

regards, Jim C

Jon Eskdale
07530 112233

Skype “eskdale”

OK. well for the moment then we just need to be aware of the limitation, but perhaps that’s something that needs to be reconsidered as it is clearly capable of definitively incorrect results.

Grand prix finishing is not unusual in single class events, and its not that unusual for Championships to be dual scored with both place and handicap results. With the Aeros doing it as a matter of course for all their open events its going to become a lot more common.

Jim C