Do you need to run rounds when results do not change?

[jbofkc]

Good evening. This certainly is an exciting time of the year. When the smell of wood shavings and aerosol paint is in the air! Ahhhhh.

Our pack upgraded to an aluminum track, electronic timer and GPRM software this year. We rent the system out and run races for packs in Kansas City. Thus far, each pack has the same format. Each den/rank races each other to determine the top three. Then things are reset and the entire pack races each other to determine the top racers of the pack and those that progress to districts. Some use points and some use times using this new system. They each run the same number of rounds. One round per age group to determine the winner. Then three rounds as a pack to determine the winners. Each used the PPN scheduling method with the GPRM software.

After reviewing the data collected and switching things between points and times to see if the outcome is any different, I came up with the following.

1 - Out of 32 total rounds, there were only three rounds that the outcome was different when scoring with points versus times. These were limited to the den races and not the pack races.
2 - When looking at each round, the top five of each round were no different from round to round. The only variance was comparing points to times scoring as noted before. Bottomline, the same cars were in the top five each round, only their finish order changed as noted above on three occasions. No one came from the back or middle of the pack suddenly. The fast were fast from the beginning.

My question is: Could we have eliminated several rounds of racing and 1 to 1 1/2 hours of event time and declared the winners earlier in the evening?

NOTE: I understand I have a limited amount of race data that has been collected. I also understand the value in just having the cars run. The boys and parents have spent a great deal of time designing and building their cars and want to see them run. Finally, there is drama with finally getting the 6 fastest cars on the track racing head-to-head, but could we have leaped over a round or two to get there?

I am curious to hear from those with more data & statistical analysis experience and if this holds true for them? Our pack race is complete and I am the rookie district PWD chair. It has been suggested to me from others to run four rounds at districts using the PPN schedule (24 heats total). Each round being fewer cars than the previous.

Perhaps, I can cut the rounds to two and get the same results even though the boys get fewer passes. At least I could at least drop one round. Expecting 65-80 cars. There has been more than a few negative comments that past races went on entirely too long - 4-5 hours to complete.

Thank you and have a great evening!

[gpraceman]

Each den/rank races each other to determine the top three. Then things are reset and the entire pack races each other to determine the top racers of the pack and those that progress to districts.

I'm a bit surprised that you are running two entirely different races.

Why not just advance the top 3 from each rank/den to a finals round to determine the top racers overall? You can cut your event time down quite a bit instead of running everyone in the pack all over again.

[Stan Pope]

A missing piece of information:

How many racers go to district from the pack? Is representation by top in pack or top in grade or top in rank?

[jbofkc]

Yes, two races. The dens/ranks go and top three from each den/rank is awarded a speed trophy. Then things are reset and everyone is entered in the pack race.

This format has been used for years in our pack. This was my first year coordinating the race and there were a number of changes, but this format was left alone. Seemed to be ok in the past. I have a different tune now that I ran the race this year and a few others. Hence, my inquiry given the data I have.

The other pack's we rent our track to establish their own format. We simply provided the equipment to run the race. It just so happens they have the same format. Den/Rank go - award trophies - then the pack goes against each other to determine the district qualifiers.

Historically, each pack sends its top three cars to the district race. The district race is not based on age/rank. It is an all in format with no separation out of Tigers, Bears, etc. I altered so many elements, that I left this one alone this year. About 35 packs in district so a little more than 100 cars with 100% entry - expecting 65-80. I have been working my PR [censored] off to promote event - see why below.

As 1st year district coordinator, I have received many, many complaints/input on several aspects of past district races. They range from track condition, timer system, scheduling, rules being released too late (18 cars did not race last year because they did not fit district rules), venue, too long, no refreshments, nothing to commemorate the boys qualifying for the race. Primarily the length of the event was the number one issue. I even had 7 conversations from entrants at last years district race that said they hope their Scout does not qualify because of their experience last year. That is just a shame.

Each of the mentioned has been adjusted to what I feel and the district professional staff feel are improvements and appropriate. They also heard the complaints and approved all my recommended changes. So far, I have positive feedback as word has spread on the event this year.

Clearly, two complete races is too much. I realize this and I take you confirm this Randy. The data was very helpful to review and help with this decision. Appears, it is best to take the top 3-5 from each den/rank and move to the pack championship round so we get some head-to-head racing of the fastest cars.

I was just curious if other folks experienced the same data pattern. That very little changes with race results no matter how many rounds are run. The top five are always the top five.

[Stan Pope]

For pack racing:

It is quite reasonable to promote the 3 to 5 "fastest" racers from each den to pack finals. For a large pack that has multiple dens for each age group, this may get to be quite a large number of finalists.

You want a high degree of confidence that the three fastest cars in the pack do participate in the finals. There is room for error among the other places, so long as the three fastest get there.

If racing by time, you might get by with advancing the fastest 3 from each den. Since cars are subject to some run time variation, 4 might be a better choice. It depends, I think, on how exhaustive the den racing is. If you run one round (one run on each lane for each car), then promote 4. If you run two or more rounds, then promote 3.

If racing by points, you should promote more, either 5 or 6 from each den since there is somewhat more error in ranking by PPN charts due to differences in opponents.

Philosophically, two runs per lane on a 4-lane track is a reasonably good outing and a good payback to the individuals who put the effort into their car. More rounds might be more satisfying for them, but time is an issue that must be balanced in. Results after two rounds are unlikely to change enough to justify doubling the amount of time (number of rounds).

Mathematically, two runs per lane on a 4-lane track is a reasonable sample of each car's speed. Statistically, a greater sample may provide more accuracy, but the time cost of the slight accuracy improvement is pretty high.

This approach also allows you to schedule the dens to arrive at staggered intervals ... which reduces the apparent event duration for the so-so cars. The best cars get more racing, and you can schedule the time for the finals to start so that those folks don't have to just sit around waiting.

For the finals...

How many rounds? I think that the same arguments as above apply. Eight runs per finalist should be plenty if running by time.

If you are running by points, then the same concerns exist as in promoting den racers, since the chart will almost certainly have a slight opponent imbalance. So, I would run the 2-round chart finals and take the seven racers with the highest finals scores into a "Grand Final" running on a PN (or CPN) chart on either 3 or 4 lanes. That is 7 (or 14) additional heats. If there are ties for 7th, either resolve the ties or exclude those tied for 7th. (Still run a 7 car chart, but include a "bye" for the 7th place car.)

I think that this cuts your total time quite a bit, still gives good accuracy, and rewards the better-built cars with additional racing.

[jbofkc]

Scored by times this year given the ability of the equipment to monitor and upload to computer. Past years was points with a homemade excel chart.

We upgraded to a 6-lane Best Track. The den/rank races were one round. Each car ran on all six lanes to determine the winner.

Makes perfect sense to reduce the number moving into the pack championship rounds. Unless things change, we will use times as this was a great change and well accepted method of scoring. Provides the best cars to move to districts and give them a fighting chance.

We have the GPRM software and used the PPN scheduling this year. I do not recall there being a CPN or PN schedule which I gather you favor.

[Stan Pope]

I do not recall there being a CPN or PN schedule which I gather you favor.

PN and CPN are special cases of PPN in which opponents are exactly balanced. Only certain combinations of lanes and cars and rounds provide charts which satisfy PN or CPN criteria. See left side of http://members.aol.com/standcmr/ppngen.html for more detail.

PPN charts satisfy these criteria:
1. Each car races the same number of times in each lane (which implies that the number of races is a multiple of the number of cars)
2. Equality of opposition is optimized, i.e., no head-to-head matchup count exceeds another by more than 1.

PN changes #2 to read "no head-to-head matchup count exceeds another by more than 0" i.e. each car races the same numbe of times against each other car!

CPN adds another criterion: "each matchup in the chart is balanced by another matchup in which the cars exchange lanes." (this is a one-to-one mapping ... no "double dipping" for any of the matchups.)

Points racing accuracy is improved (though still not 100%) by running on the special cases of PPN which satisfy PN or CPN criteria. So, when possible, I prefer to do points finals on PN or CPN charts.

Examples of combinations of lanes and cars that produce PN charts:
Lanes Cars
2 3
2 5 (2 rounds)
2 7 (3 rounds)
...
3 3
3 4
3 7
3 13 (2 rounds)
3 19 (3 rounds)
...
4 13
...
5 21

Each of these charts has a CPN sibling with exactly twice as many heats.

Why so few? It's a "number theory thing!"