If it is coming from a bookie they would be referring to what they win, this might answer the question.

I don't think race filter works as a general criteria but more in the type of selections you have.

If you were going after favs you might consider earlier races on the program but if you are after better prices later races might be better.

When i was more in to ratings Open races and above were always better for me, maybe it was the exposed form or more prize money that ment horse were more inclined to race on merit.