I love puzzles so when I woke up at 3:30AM and couldn't get back to sleep, I asked myself, how could someone cheat at a marathon year after year and not get caught. Here' my thoughts.
Marathon Cheating 101
Assuming someone wanted to cheat to run a sub-3 marathon. How could it be done over and over without getting caught?
1. Find a suitable course. Become intimately familiar with it, including how the course could be cut or how a runner could be ferried between 5k mats by car.
2. Determine your desired finish time.
3. Determine realistic splits to achieve that time, accounting for slowing at the end and hills.
4. Determine the best exit and reentry points to hit every mat. Ideally, it should be where exits and reentries wouldn’t be noticed much, such as at a corner, near a porta potty, or after a water stop when walking runners would toss their cups and start running again.
5. To facilitate multiple exits and reentries, wear a bib belt and floppy clothing to hide the belt so no one will see it when you exit/reenter the course. Keep the bib hidden except for mats and known photo points. Even if someone sees you, they won’t have a race number to report to the race director.
6. Wear a disguise… a cap, sunglasses, clothing that doesn’t obviously scream “elite runner” when you’re off the course, and clothing to hide the bib belt.
7. Don’t start up front. Wait a while and then get lost in the crowd. More people will be on the course so the first few exits and reentries will be less likely to get noticed. Alternately, you could skip the START entirely and have a mule carry your bib across the start line, exit, and then ferry the bib to you before the first 5k mat.
8. Start your watch when your mule starts or when you start if you actually start the race.
9. Cut the course soon after crossing the start mat. Call your driver to make sure he/she is at the designated pickup location.
10. Have an accomplice who drives you to the next entry point or take a short cut, depending on the course. (Driver leaps forward to next ferry point after dropping you off.)
11. Walk to your reentry point. Check the time of your last split on your watch. Time your reentry into the race to hit the next mat at/near your desired split time.
12. After the mat, exit again. Get ferried or cut course to get to some point before the next mat.
13. When runners get far apart, reentering the course could get noticed so when practical, jump in after a group passes by to make your reentry less obvious to spectators. Adjust your pace accordingly to hit the next split at the appropriate time.
14. Repeat steps 9-12 until the 40k mat.
15. Reenter before the 40k mat and run to the finish yourself. This could be your longest run of the day, but runners slow at the finish so even if you’re a minute slower than your previous splits, it’s believable. Make sure your bib is visible at the finish.
Regardless of planning, two things would be unavoidable. 1) Official photographers switching their previous location or adding a new location. You wouldn’t show up sequentially or at all on their race photos unless they were really close to the timing mats before you cut the course. 2) Leapfrogging runners who pass you on the course, perhaps multiple times. Still, as long as you’re not in their age group, few runners would care so it wouldn't get reported.