I don't know, but it is a good idea. You can get the winning favorites for each track at
www.ustrotting.com, go to results, track statistics, and it has the post position stats and stats of winning favorites. I like to see favorites winning at less than 40%. I'm amazed that tracks that have a high percentage of winning favorites don't try to make changes to cut down that number. The only track that seems to be able to generate decent handle with a lot of favorites is Northfield, which is at 47% for the year. But that's an outlier. Normally the better the payoffs, the higher the handle.