Have tried this on many tracks, hit big at Louisiana Downs for over $19,000 on a $1 Superfecta box. Also have hit twice in about six races for big winners on Australian races. Other big scores have come at Woodbine, Saratoga and Evangeline Downs. Has not worked well at all for Del Mar and Monmouth.
Good Luck and thanks again for sharing. There is a free TVG website where they give you $1000 in fantasy dollars to wager on all the racetracks here and overseas. They keep track of your wins and losses for you and found it to be a great area to test systems without risking real money. tvgfree.net is the website.