The Detweiller Report: A Look Back In Course Measurement

Frequently Asked Questions (FAQ)

Q: Why is this important?

A: This is the most important high school cross-country course in the state of Illinois. Besides the State Final, it hosts at least three large invitational meets earlier in the season. The quality of cross-country in the state is evaluated based on performances on this course. The course has a reputation of being short, and performances on it are discounted for that reason. This costs Illinois athletes deserved national recognition - and possibly some attention from college coaches.

Q: When USATF measures a course with a calibrated bicycle, don't they add some distance just to make sure the course isn't short?

A: When a new course is laid out, USATF requires that a Short Course Prevention Factor (SCPF) of 0.1% (one meter per kilometer) be added to the course to insure that it isn't short. However, when measuring an existing course to determine its actual length (for example when a record appears to have been set), the SCPF is not used, and it was not used in the measurement of the Detweiller Park courses.

Q: When measuring with a steel tape, aren't you supposed to correct for temperature?

A: You are. However the correction is rather small, especially when measuring on a hot day like July 19 was. Assuming a temperature of 86 degrees Fahrenheit or 30 degrees Celsius, the correction works out to about 4 millimeters over a 50 meter tape length- or about 40 centimeters over a 4800 meter course.

Q: It is generally accepted that the "new course" is about 9 seconds slower than the "old course". Is there a reason for that?

A: Our data does not show this. The pre-2003 and post-2004 courses are approximately the same length. In fact, some of the changes to the course would tend to make the current course faster than the 2002 course. The start and finish aren't as far up the hill, which essentially makes the course flatter. And the changes also smoothed out some of the turns, especially in the north loop, which should also facilitate faster times. Our preliminary data on the 2003-2004 course shows that it was about 20 meters (0.0125 miles) longer than the course that came before or after, or 3.5+ seconds slower.

Q: Didn't the first turn used to be defined by some trees?

A: It did. Before the 2006 race, however, the trees were cut down and new trees were planted south of the former location of the old trees. The IHSA apparently had the Peoria Park District fabricate some poles and placed them in sleeves in the ground in the location of the old trees. The course in the first turn is now defined by those three poles. The sleeves are set in concrete, and are not hard to locate if you know about where they are. We were able to find them easily on July 19.


Q: Could the course have changed from 1972 to 2002?

A: Absolutely. Most of the landmarks that define the course are trees. The trees (especially the evergreens) are larger at their base than they were in 1972. There are trees in the 2002 aerial photograph that aren't there now. There are trees that define the course that definitely appear to be less than 35 years old. For the sake of discussion, if, due to tree growth, the radius of all of the turns on the course increased by 1 foot from 1972 to 2002, the overall length of the course would have increased by over 9 meters. That's between one and two seconds for almost all of the runners who run in the State Final.

Q: For years, coaches have been wheeling this course, and they've almost always found that it's short. Are they all wrong?

A: Not necessarily. If you measure this course over the shortest possible route a runner can run, it is indeed short of three miles. There are issues with the wheel as a measurement device, especially on grass, and there are differences between the line that most coaches "wheel" and the line the IHSA chose to measure. Most of those would tend to make the course measure shorter than it actually is.

Q: Why isn't there more data on the 2003-2004 course?

A: There is more history on the 2002 and prior course, and the 2005 to present course is memorialized with monuments at Detweiller Park at the start, finish, every half mile, and at those places where natural landmarks do not define the course. There is much less available documentation about how the course was laid out in 2003 and 2004. We believe that, except for the fact that there was only one creek crossing instead of two, the course was the same as it has been since 2005. But either the start or finish could have been moved in 2005 to its current location, and any physical evidence of the change would no longer be there. Or, NFHS rules being what they are, the IHSA simply could have defined the course as being a few feet wider in 2005, in which case it would be the same distance as it was in 2004.

Q: So, did Chris Derrick and/or Craig Virgin run a full three miles?

A: It's hard to say for sure, but most likely neither did. Someone running far enough ahead that he or she sets a course record probably isn't running in a pack after the half mile mark and has his or her choice of lines. It's doubtful that they would have consistently run a radius on the corners large enough to approach the line that would be necessary to make this a full three-mile course.

Q: Who ran faster, Derrick or Virgin?

A: Your guess is as good as ours. The data shows the courses to be about the same length, and one definitely can't conclude that the course was significantly longer or shorter in 2007 than it was in 1972.