Over a long period racing's CYCLICAL moeee, and running just one system is a cerain way to lose. When you have the inevitable run of outs you'll either bail too early through 'fright' or you'll go down with the ship, or you'll alter the rules to suit the current environment, only to discover that the system returns to the long term trend. See the financial markets for an example of a CYCLICAL nature moeee. You've got no safety net moeee so if your system starts to trend differently, you wont know if it's permanent, or short term, and that's a recipe for financial disaster. macs has the perfect scenario here I believe. He has approx 20 bets per year for each specifically targetted system (I assume the rules are logical and consistent), and the number of systems allows him to monitor them individually and collectively and ride out the rough times when a few systems turn bad, only to find that are few others outperform. Monitoring these systems as a group will also throw up data from many varied sources (obviously 'coz you've got many different rules over the 37 systems) and useful information covering the whole gammit of racing can be analysed. It's so much better than analysing just one set of rules moeee. It's like talking to a house brick .....