I once subscribed to a couple of ratings services. What a blunder. They certainly wouldn't want to be betting using what they sold. They regularly advertised big overlay winners. Here's what they did. In most races they had the favourite way out or not even in their ratings. They even justified this to their members by telling us that as the favourite loses two out of three races, the way to go is bet against the favourite. That huge value can be created by taking a different approach to the majority of punters who lose by backing favourites and instead taking on the favourites. When they were lucky enough to pick the winner in their top five they advertised a big value overlay winner. They forgot to tell you that in most of those races you'd be betting five horses, because they were all "value" once the even money favourite was left out or priced at 15/1. They also forgot to tell you that you'd be wiped out every time the favourite won and every time they missed the winner in their top five. But you saw plenty of ads like "rated 2/1 wins at 5/1."