yes it breaks down exactly like that. over the long term the best wy to find the most frequent winner (or rank the winners liklihood of winning is by money line.) And its almost nuts on -160 win at about -155 -130 win at about -125 etc. etc. etc.
Same is true almost exactly in horses. the best prediction of a horses chance of winning are his closing odds (with trakc take out factored in) if you look at every race, every day. the 6-5 win more than the 8-5 and in that exact ratio.
This is not to say every line is exact and not any overlay opportunities, there are many of them, Im talking about if you consider all the lines or all the horses.
spot plays (are blips on the radar screen)