Cathy I use some software that I got years ago, the company is now out of business (draw any conclusion) but of the last 3 Melbourne Cups I have 2 Quinellas $270 & 240 and 1 Trifecta $6000+. I prefer the human touch when selecting rather than using someone else's set of rigid rules. Might I suggest that you develop you own set of rules, one of the racing publications has software and a database to allow this.
Jim