Depending how big your database is, you could use the approach I used to determine the importance of variables.

I admit it's a rough and ready method but once you have the results it's easy to refine.

This is the method simple but takes time, determine your handicapping factors/ideas, I came up with about 30.

Order them in descending or ascending order according to whether you set min or max point for best.
Run them through your database one by one and print out the final results win% place% for as many selections as you deem important.
I used the top four only.

The nuts and bolts are dependent on what programme you use I use C in .net.

The outcome is quite interesting, some factors almost win outright but for the TAB takeout give or take a few %, some are mere punter's myth.

It takes time but worth it, you could do worse.