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Credibility of the Pinewood Derby Race

As a derby leader, I am very much aware of race credibility. Every
participant in a derby wants to know that the race is completely fair, so
the derby leader must take every precaution to ensure that there is no bias
in the race. To the race participants, the race procedures must be above

Race bias can come in three ways:

- Intentional: A car or group of cars is unfairly treated by a race
official (hopefully this never happens)

- Unintentional: A car or group of cars is unfairly treated due to poor
race procedures

- Perceived: Even if all cars are in fact treated the same, a race
participant or audience member can still believe that an entry is being
treated unfairly.

To run a race with integrity, the derby leader must make every effort to
eliminate all of these forms of bias. Below are guidelines you can follow to
keep your race above reproach. Remember that the goal is not just to
eliminate race bias, but to also eliminate any perception of bias by the
audience and participants.

Race Rules

Complete - The race rules must be complete. Thus, the rules should specify
all car dimensions (maximum height, maximum overall width, minimum distance
between the left and right wheels, maximum length, bottom clearance, wheel
base); and allowed/disallowed wheel treatments, axle treatments,
accessories, and weighting methods.

Specific - If the intent of your rules is to ban specific design techniques,
then the rules must specifically do so. If the rules do not specifically ban
a particular technique, then entries using that technique should be allowed
to participate. For example, consider the following rules:

1. A light sanding to remove flaws is allowed as long as the wheel retains
the original width, diameter, and shape.

2. The wheels may be lightly sanded.

Rule 1 is very specific as to what can be done with the wheels. A car with
narrow wheels would clearly be disqualified from a race using this rule.

On the other hand, rule 2 is ambiguous and could lead to problems. A car
with narrow wheels should be allowed to participate, since the rule does not
disallow narrow wheels.

As an example of the need for complete and specific rules, one person wrote
to me stating that they wanted to remove material from the wheels. This
particular technique was not mentioned in their rules, so they asked a race
official (not the head official) if the technique was allowed. The race
official gave them permission. But at the weigh-in, the head official
disallowed the technique, and the car was banned from the race. This was
clearly a case of unintentional bias (hopefully it was not intentional), and
could have easily been eliminated with clearly written rules.


Dual Officials - Since race officials typically are the parents of one of
the entrants, always have two officials perform the car inspection,
including weighing the cars. These two officials must not be related to
each other.

Official Weighing Method - Regardless of the type of scale you use, make
sure that all cars are weighed on the same scale, and that the method of
weighing is consistent for all cars. With our postal scale, instances have
occurred where the scale display alternated between 5.0 and 5.1 ounces.
So, our policy is that the scale must consistently show 5.0 ounces or under
for 5 seconds before the car's weight is consider official.

Scale Location - Locate the official scale on a solid surface, away from any
air ducts. Both airflow and a shaky surface can affect the readings on
sensitive scales.

As an example of this problem, during one check-in our scale was located
under an air-conditioning duct. Whenever airflow was present, the scale
would read a slightly greater weight! Once we realized the problem, we
covered the duct. But we had to reweigh all of the cars to make sure that
everything was fair.

Car Storage

If your check-in occurs immediately prior to your race, then storage is not
an issue. But in some races the race evening is shortened by holding the
check-in on a prior night. The cars are then stored until the race.

To ensure that our race is above reproach, two non-related officials store
the cars, and then put a 'seal' on the storage area. On the night of the
race, the same two officials check to make sure the seal is not broken. The
'seal' can be as simple as an adhesive label placed across the opening of
the storage cabinet. The two race officials then initial the seal.

This process may seem excessive to you, but if a parent ever asks how we
ensure that no tampering occurs while the cars are stored, we are ready with
a good answer.

Race Format

Race formats can also introduce bias. We will be covering race formats in
much greater detail in future articles, however here are some basics.

Elimination Method - Elimination methods can accurately determine the
fastest cars if the number of lanes is taken into account. With a two-lane
track, a double elimination method can only determine the top two cars, not
the top three (the third fastest car could get eliminated early by racing
the fastest car and then the second fastest car). So with a two-lane track,
third place must be determined by rerunning all eliminated cars. With a
three or four-lane track, third place can be determined as long as the top
two cars in each heat 'win', and the third and fourth place cars (on a
four-lane track) 'lose'.

Stearns Method - Stearns and other rotational methods are good at finding a
group of the fastest cars, but cannot guarantee the trophy winners unless
all cars race all other cars an equal number of times and with equal lane
use. For a small number of cars, the Stearns method can work well. But for
a large entry field, the Stearns method could take a prohibitive amount of
time to determine the winners. In our race, we resolved this by using
Stearns to identify the top group of cars, and then follow with a double
elimination to determine the trophy winners.

Lane Bias - Generally, one or more lanes on a given track are 'fast', while
one or more lanes are 'slow'. Thus, with any race method, it is important
to randomize/equalize lane use. With Stearns and other rotational methods,
lane assignments are randomized or rotated. But with Elimination methods,
care must be taken to randomize lane assignments. One way to do this is to
have the entrants draw lots for the lane assignment prior to each heat.

Car Handling

One of the worse things that can happen in a race is for a child to drop
their car. But even worse is for one of the race officials to drop (or even
mishandle) a car! Thus, use a race procedure whereby the officials rarely
if ever touch one of the cars. This means that each car owner picks up
their own car from the staging area, places the car on the track, and then
returns the car to the staging area at the end of the race. In the case of
very young or disabled car owners, parents or a sibling can take on the car
handling responsibility.

Finish Line

Manual Judging - Clearly, if an electronic finish line is not available,
then two non-related judges must judge the races. The judges must agree on
each finish, or the race must be re-run. If one of the officials misses the
finish or cannot distinguish the winner, then rerun the heat. Don't allow
one judge to defer to the other.

Electronic Judging - For finish lines that display the results to the
audience, no special precaution is required. However, some finish lines
display the results on a remote module, or directly enter the results into a
computer. In any case where the results are not instantly displayed to the
audience, two non-related judges must monitor the results.


I realize that to implement all of the above mentioned precautions will take
extra work on the part of the race official. However, you must ask yourself
one question. If a parent came to me and said, "My child's car is being
treated unfairly," what would you say? If you have implemented all of the
precautions above, you can ask the person to clarify, and then explain how
the precautions you have taken ensure that each entry is treated fairly.
But if you have not implemented all of the precautions, ...

From Pinewood Derby Times Volume 1, Issue 9

A pinewood derby memory is an occasional part of the Pinewood Derby Times Newsletter. To subscribe to this free e-newsletter, please visit:

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