Originally Posted by
genejockey
A model has predictive value, or it doesn't. There have been lots of counter-examples, not just one or two. And again, the examples take place in the real world.
You can't say it's representative of the real world, if the real world keeps doing something different.
Counter-examples to what?
There have been counter-examples to the 43 mph rule, which is OK because the rule was specified with caveats about wind, altitude, and body weight. There haven't been any counter-examples to the general validity of the calculator itself. If someone comes and says "I weigh 160 lbs and I can hit 50 on a 8% slope at sea level with no wind", and it can be verified that he in fact hit 50 with no wind, that would be a counter-example and would indicate that something is wrong with the model.