What type of scheduling?

Debates and discussions on the various race scheduling methods that can be used and their fairness and accuracy in determining the winners.
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What type of scheduling?

Post by *5 J's* » Mon Apr 06, 2009 6:49 am

Just completed Pack & District races - each used totally different methods. I see some pro's and con's for each. I am searching this forum to find others views of the pro's/con's, but I'm not sure what the name of the methods are.

Can you tell me which methods were used below?

PACK
First - at the Pack we had 25 cars competing on a two-lane track. Each car was assigned a number a check in. In a "preliminary" round car #1 raced against car #2, etc. Each car ran in lane 1, then in lane 2 - and is scored the average TIME. Then in a "time trial" round the fastest two cars ran against each other, then 3rd against 4th, etc. until all cars ran. At this point all cars had run four times - the first two times totally random - the second they were paired up more evenly (giving lower cars a chance to win at least one race).

At this point the top sixteen cars were announced. These sixteen were bracketed (1 & 9, 2 & 10, 3 & 11, 4 & 12, 5 & 13, 6 & 14, 7 & 15, 8 & 16). These cars ran against each other twice (once in each lane), and one car would be eliminated - one would go on to the next round. 16 cars would go to 8, then to 4, then to 2, where the winner was identified.

DISTRICT

At the district there were approximately 80 cars running on a four lane track. Again the cars were assigned sequential numbers at check in, but this time the cars running against each was random in the first heat. Five rounds(?) of 20 heats(?) were run with the winner in each heat given 7 points, 2nd place 5 points, 3rd place 3 points, and 4th place 1 point. At the end of 5 rounds four cars had 35 points (lost no heats) and four cars had 33 points (came in second one heat). I am assuming that each round the lanes and pairings were systematically rotated.

At this point the top eight were announced and they ran against each other in two car heats. Each car would continue to run heats until it lost twice at which point it was eliminated. This continued until the winner was identified.



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Re: What type of scheduling?

Post by Stan Pope » Mon Apr 06, 2009 7:55 am

For your pack race:

What was the rule for pairings in the 2nd. 3rd, and 4th rounds of the finals?

How many trophy places were identified?

For your district race:

In the preliminary races, do I understand correctly that each racer ran once in three of the lanes and twice in one lane? Or was lane balance not a factor?

What was the rule for pairings in each of the rounds of the finals?

How many trophy places were identified?


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Re: What type of scheduling?

Post by *5 J's* » Mon Apr 06, 2009 9:57 am

Stan –

For the Pack - three trophy places were awarded (1st, 2nd, 3rd).

The pairings started by taking the top sixteen fastest and pairing 1&9, 2&10, 3&11, 4&12, 5&13, 6&14, 7&15, and 8&16. After that the eight winners are paired up in accordance with the tree below. Note this reflects actual results with names removed.
Image

For the district


Eight positions were identified for the finals, as four were tied for first with no losses in any of their five races, and four were tied with four wins and one second place in their five races. (The hope was to have six – but it didn’t work out this way using points for the first task was to eliminate two of four tied.) They had 5 trophies and one medal to award the top six drivers.

Yes – I believe each racer ran once in three of the lanes and twice in one lane to try to balance lanes. I’m not sure how they were paired up for the finals, but I do know they ran two cars at a time (vice four as was done in the preliminaries).



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Re: What type of scheduling?

Post by Darin McGrew » Mon Apr 06, 2009 10:44 am

*5 J's* wrote:Can you tell me which methods were used below?
For the pack race, it sounds like times were used to seed a single-elimination bracket. It sounds like a lot of work for a system that identifies only first place accurately.

For the district race, it sounds like a points-based PPN-like system was used, although I find it odd that the number of heats used wasn't a multiple of the number of lanes. That means that they did not assure that each car raced the same number of times on each lane. Then the results of the PPN-like system were used to seed a double-elimination schedule. Again, it sounds like a lot of work for a system that identifies only first and second place accurately.



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Re: What type of scheduling?

Post by *5 J's* » Mon Apr 06, 2009 10:57 am

Darin McGrew wrote:For the pack race, it sounds like times were used to seed a single-elimination bracket. It sounds like a lot of work for a system that identifies only first place accurately.
I will add that the ranking based single elimination was (by car number) 2, 20, 18, 21, 5, 19, 22 whereas by average speed across the elimination rounds: 2, 21, 18, 20, 22, 19, 5. So as you can see - the fastest (avg) car received 1st, however, the second fastest (avg) was ranked 4th, the third fastest (avg) was ranked 3rd, and fourth fastest (avg) was ranked 2nd.

Obviously this points out a "con" of this method. Another is that as kids were eliminated they soon lost interest in the derby.
Darin McGrew wrote:For the district race, it sounds like a points-based PPN-like system was used, although I find it odd that the number of heats used wasn't a multiple of the number of lanes. That means that they did not assure that each car raced the same number of times on each lane. Then the results of the PPN-like system were used to seed a double-elimination schedule. Again, it sounds like a lot of work for a system that identifies only first and second place accurately.
I found it odd that we ran an odd multiple of heats - I would have thought with four lanes, you would run either 4, 8, 12, etc.

Is there an overall consensus as to the best method to (a) keep the kids enthusiastic (b) identify ranking accurately (c) make is logical to understand the process?

Or is this a matter of great debate?



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Re: What type of scheduling?

Post by *5 J's* » Mon Apr 06, 2009 11:01 am

Just to be clear - there are no sour apples here. My boy was car #2 and won at the Pack level and placed a very respectable 9th at the District (with three wins and two seconds in his five heats).

My interest is understanding the pro's and con's of each method - and potentially finding a "better" method that I could implement at the Pack level.



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Re: What type of scheduling?

Post by azgreg » Mon Apr 06, 2009 11:06 am

I allways felt that pairings for a single elimination bracket should be 1 vs 16 down to 8 vs 9 just like in drag racing and the NCAA basketball tournament.



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Re: What type of scheduling?

Post by Stan Pope » Mon Apr 06, 2009 11:08 am

*5 J's* wrote:Or is this a matter of great debate?
Yes! We can't even agree on what "fair" means!

As Darin observed, though, there are some basic concepts to be considered. Accuracy is among them. Enough racing for each participant is important, too. Fairness is sine qua non.


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Re: What type of scheduling?

Post by *5 J's* » Mon Apr 06, 2009 12:33 pm

Darin McGrew wrote:For the pack race, it sounds like times were used to seed a single-elimination bracket. It sounds like a lot of work for a system that identifies only first place accurately.
Thanks Darin - I think I will start my search of this forum for the pro's and con's of the single-elmination method as I could most likely affect change at this level (pack) if required. We do eliminate the issue of preferred lanes by having the cars swap lanes each race and using the average speed. However, I do see some other con's with this system
Darin McGrew wrote:For the district race, it sounds like a points-based PPN-like system was used, although I find it odd that the number of heats used wasn't a multiple of the number of lanes. That means that they did not assure that each car raced the same number of times on each lane. Then the results of the PPN-like system were used to seed a double-elimination schedule. Again, it sounds like a lot of work for a system that identifies only first and second place accurately.
Once I understand the pro's and con's of the single elimination method I will search for the pro's/con's of the points based PPN system. One concern I had in the way our district implemented this was that we did not run each lane an even amount of times. One other issue I had was other than knowing you had finished in x position y number of times, the kids really had no way of judging how well or not they were doing. I could see the kids losing interest in the racing.

Definitely whatever method I perceive to the be the best will take into account fairness, interest for the kids, and accuracy. However, to some extent as long as it is fair, I can see reasons to give weight to interest of the kids over accuracy.



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Re: What type of scheduling?

Post by Stan Pope » Mon Apr 06, 2009 1:28 pm

Here is a short "memory dump":

Darin has some good method comparisons on his personal web site, http://www.rahul.net/mcgrew/.

Accuracy would appear to be a simple concept, but it isn't. There are value judgements involved with measuring accuracy. An example is how do you value consistency from run to run? Another is how do you value "staying power?" (By that I mean the ability to keep running fast even after 10 heats, 15 heats, ... Different cars and lubes show speed decay with different patterns.)

PPN is one example of final standings charted methods. Stearns and Lane Rotation are others. All PPN charts are good for timed racing. Most PPN charts are good for points, although most are better for preliminary racing rather than for finals racing.

Timed racing would appear to be a "hands down" choice for accuracy, but there are some real "gotcha's" waiting to "bite you in the, ummm, backside." My district tried it (over my advice) a year ago, and awarded a first place trophy to a car that never finished better than 3rd in his four heats and left early knowing that he was way "out of the money." This year, Terry's district had a similar error, although the car that received the 1st place trophy was at least a quality car and would have finished 3rd or 4th. Both were due to equipment malfunctions which were not recognized until after the racing was over and the participants gone.

In introducing change, there is value in retaining a strong component of the pack's/district's tradition. Careful, incremental improvements rather than massive revamping tends to be more acceptable to the crowd. They understand the "way it works" and, hopefully, can see that the changes are, in fact, positive.

Youngsters tend to be more interested in "doing it themselves" rather than "watching someone else doing it." Putting on my 9 y.o. hat: Watching someone else race my car is marginally more interesting than watching someone else race other cars. And watching them race when I am convinced that I am out of the running is really boring. Consequently, methods that try to keep everyone around until the end are doomed. (Unless they are hoping for one of the hardware hiccups mentioned above.)


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Re: What type of scheduling?

Post by ScoutAndDadTeam » Mon Apr 06, 2009 3:07 pm

Both were due to equipment malfunctions which were not recognized until after the racing was over and the participants gone.
Stan, Please identify what the equipment malfunctions are and how to avoid them.



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Re: What type of scheduling?

Post by Stan Pope » Mon Apr 06, 2009 3:37 pm

ScoutAndDadTeam wrote:
Both were due to equipment malfunctions which were not recognized until after the racing was over and the participants gone.
Stan, Please identify what the equipment malfunctions are and how to avoid them.
Both involved improperly low heat times. In my district, the time for one lane was approx 1.0 seconds low. Cause apparently loose connection to electronics. Alert, knowledgeable track staff should have caught that error. It was really gross. :( But, since few announcements and no displays, there was no way for anyone other than the "man at the computer" to apply any sanity checks. Even with the unreasonable time, the racer still finished 3rd or 4th in the heat. Others had more typical times assigned.

In Terry's district one of more heats were timed at approx 0.1 seconds low. Each racer showed a similar distortion as compared to their other runs. The error was confirmed by video review, timing frame-by-frame. The error was enough to move one racer. Alert, knowledgeable staff might have caught this error, but it does not jump out at you unless you realize that the winner's time was 0.05 sec better than the track record. Sticks out from data analysis, and justified from the vid. Cause at this time is not know, but probably associated with start signalling, such as a sticky microswitch.


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Re: What type of scheduling?

Post by Darin McGrew » Mon Apr 06, 2009 4:04 pm

Stan Pope wrote:In introducing change, there is value in retaining a strong component of the pack's/district's tradition. Careful, incremental improvements rather than massive revamping tends to be more acceptable to the crowd. They understand the "way it works" and, hopefully, can see that the changes are, in fact, positive.
Yep. Several years ago, at my suggestion, we switched our race method from simple lane rotation to a PPN-like schedule. There are several advantages to the PPN-like schedule (better accuracy, never scheduling cars in 4 consecutive races, more races per car), and no one would go back to lane rotation now, but there was a lot of inertia to overcome at the time. And ultimately, the only things we changed were the way races are scheduled, and the number of races per car. Everything else remained the same.

I'd still like to use the PPN-like schedule to pick finalists, and then use a CPN schedule to determine finish order among the finalists. But that's a harder pitch to sell.



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Re: What type of scheduling?

Post by davem » Mon Apr 06, 2009 7:53 pm

One way to introduce the change is with the addition of a computer to the race.

If the race organizers want the race to be more efficient (i.e. quicker), and appealing to the crowd (easy to follow) - a computer and race program can answer that call - and introduce the opportunity to race by times or points.

With a 2 lane track - my approach (if money weren't an issue) would be to help raise funds for a new 4 lane track, with a new timer, and computer program to:
1. give the racers more heats
2. reduce the time of the total event
3. get the crowd involved with computer graphics (and instant replays)

Worked for me twice now.



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Re: What type of scheduling?

Post by davem » Mon Apr 06, 2009 7:57 pm

One other thought.

I have run races using both points based scoring and time based scoring.

I prefer points and PPN because the results are visually verifiable by the crowd.
However, most people - when given a timer - will want to race by times.

When I run timed races - several people want to examine the times in detail (some looking for errors).
When I run points - haven't had anyone question the results yet.



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