Duritz,

Yes I see what your saying, it's a damn confusing puzzle and has had me hitting my head against my desk.

Robohorse's non-win is not just as good because he was beaten by a better (faster) horse, however he will run the same time and win a race, so you have to rate him objectively.

If the ratings method just said "The class figure for a listed wfa race at flemingon is 64 kgs, he carried 6 over the limit, so week one he rates 70, week two though he rates 67 due to the margin" then it is WRONG, because RoboHorse does the same rating every week.

No some ratings are based on lengths beaten on the strength of the race and lengths beaten. You're still missing that he was beaten by better horse. I think you need to apply a base rating to a wfa at flemington BUT also adjust it for field strength so you get a more accurate rating. This is the key.
Your rating for the losing run should suffer, his run was not as good because he was beaten by a better horse, even though he would win 9/10 times etc.