woof43, a very valid point. I try to compensate for this by overestimating the decline in speed over distance. Also I don't bet on anything where the average distance on previous races(3) is more than or less than 10% of the current race. Still learning and taking stats on this, I might indeed have to change this, maybe to within 5% or something.
Still looking at your other comments about standard deviation and so forth, but might take awhile to work out how to do all that in excel.