In reply to Every Topic:
The approach I am developing is to-
1) Get a horse's actual last 600m time using the Sportscolour web-site, ignoring the occasionally crazy times they post.
2)Adjust this time for the Daily Track Variant i.e. the fastness/slowness of the track on that day.
3)Compare the adjusted time with the Par time for that track/distance and thus obtain a rating for the horse.
4) Adjust the rating for the pace of the race.e. g . if they crawl for the early sections of a race the last 600m will naturally be proportionally faster than normal so the rating should be down-graded.
Of course the integral part of the whole deal is determining the par times and the standard % that the last 600 represents of the total race time.
Hope this gives you some ideas.