Predicting running racing times is just for academic value

Many training portals for running calculate racing times from all accomplished running workout results.
The most accurate way to predict a finish time is outgoing from prior performances in races. But there is no way to classify races in most training portals.
However the mileage in front of a race does matters. The first finishers are running significantly more kilometers in training than all other runners.
Another variable in predicting race outcome is the number of races a runner has completed.
Experience with a distance, specific pre-race planning, tapering, carbohydrate loading or strategizing during the race are essential.
The current weight of a runner should be also considered (10kmlauf.blogspot.com - Loosing weight to be competitive).
Gender is important, because women do it better on long distances (alsoranrunners.info - How to run the Comrades Marathon; 10kmlauf.blogspot.com - Ultra high).
Last but not least the track and weather conditions are factors.
In total all this is hard to measure by an algorithm. But it is not impossible and all training portal don't even try to consider more than a handful of all the factors.