Just to add to this topic because i am bored.....that was writen a long time ago about 10 years if i am correct and the bookies that were stated i think operated in the early 70s.
Things were a bit different back then they would get different prices from different bookies as to keep the percentages under 100% they also played on the fact that would get the winner earlier in the races when the percentages were in there favour rather than later we all know what would happen if you get to the last race with this idea.