Reportedly, many professional players envision the running of a potential race over and over to determine how often a selection should win. All things being equal, this gives them enough information to construct an odds line. At post time, if the selection goes off at or more than the line it's a bet. Otherwise, a pass.
Nice idea. But. I don't have that kind of time and I'm not sure I would enjoy the game as much with the necessary extra work. I'm still trying to find enough time to really examine daily result charts.
I know that favorites are created by the public--usually based on a top Beyer fig, a good recent performance, or public selector. I am willing to look behind the obvious--trouble lines, previous wins at the distance, etc.
Still, unless Secretariat is running against the average claimer, I never understand a reason for odds of 3-5, 0r 4-5.
I set my target odds at 6-1. If my selection is a 'move,' I'm confident when odds are around 9-1 (the average). Selections longer than 15-1 require a smaller bet.
What are your good odds? However you arrive at a figure, at least have an idea of what odds are typical for your play.