Yes, there are races shorter than anticipated. I am not referring to the case you go out for a 10K, and you end tired or drained after 5-6K. Or, even worse, when you arrive home with your GPS tracking system stating you’ve run 9.89 km. I usually run an extra block to have a round figure… or sligthly above.
Here I am talking of official events, that turned out after a recheck being shorter, and therefore not valid for omologation.
Recently, runners of the Leeds Abbey Dash 10K race have been told that finishing times will not be officially recognised, because the 10km course was 23 metres too short. 23 meters, yes. The event led 8000 runners on Leeds’ streets, gathering money for charity events.
This is not an unique event. The Manchester Great Marathon of 2018 was found 380 meters short after recheck, affecting 24000 runners who participated in three editions, from 2013 to 2015.
The Athletic Federation establishes clear rules for race distance calibration. The only approved method is a bit old-fashioned, and it is through a calibrated bike (yes, a bike) and a funny mechanism called Jones counter. This is basically a gear with a counter, nothing fancy or high tech, and was invented in 1971 by Alan Jones. Much different from the technical support that helped Kipchoge to write history in the Ineos Challenge.
The procedure is very detailed, asking to use the shortest possible route (that is also why we end a race always above the declared distance!), and taking into account details like bike tire pressure, room temperature etc.
Tolerance are clearly regulated. There is even a rule asking to add a +0.1% estimate to reduce risk of short races. In other words, to measure a round km, it is required to measure 1001 meters.
All very detailed, but not enough to avoid uncertainties that led to cancellation of official timing… for 23 meters.