Just seems like yesterday (2003 or around that time when I raised this same issue, fast forward a decade and here we are again).

First up, most this isn't really going to be helpful for the "backfitters" here as most continually mix Strike rate and ROI together. Remember Strike Rate only applies to Handicapping/Rating and ROI applies to Wagering.

It's not too hard to develop a list of variables or a combination as all have been listed here previously in database threads and just putting on your "joe public thinking cap" instead of the computer handicapper cap, you should be able to develop your list.
To know how the crowd looks at all handicapping variables, you have to test each one and then see which one or combination they use or the ones they don't use. To do that you need to build a generic , single factor simulator that can give you probabilities studies for each factor. All you will do once you have run a test is to determine the relationship between each factor and the crowd odds (not strike rate, not ROI just plain simple ODDS) Using a simple application of multivariate analysis will do this easy.
A simple test is to use the above to determine a set of "win" probabilities and then plot them against the actual post time odds in a scatter diagram, all you do then is to use Correlation Analysis and Correlation Coefficient and you will be on the road to success.

Just remember. for crowd "measures" accurate means close to actual odds , not observed finish percentages