The times for 1000-1200 metre races have a similar look when dissected to those of humans running the 100m. The first quarter is a build up to top speed which is maintained for the second quarter. The last half is deceleration. Those horse that "flash" home and indeed the human runners that do the same are merely decelerating at a lesser rate than the others. It would be extremely rare in a sprint race for a final sectional to be quicker than the 800-600 split unless they trotted early.
I dabbled with those sportscoluour sectionals for a while and needed strong medication to sleep at night they were so mind boggling.
There are definately easier ways to make a buck on the punt.