I don't even go along with the over bet argument.

I believe that the betting market generally provides a very accurate summary of each horse's chance in a race, and horses will win in proportion to these prices. All the ratings, systems, opinions etc that Barny mentions factor in most of the available knowledge about a race and are used by punters to produce these prices. What makes it difficult for punters is the take so in the main punters will lose.

This is why I agree with Barny that something radically different is needed, not so much to get overs but rather to know when a particular horse will win regardless of its price, because as I have said, the price is most likely right. Inside info would help but that is not available to most punters.

I have found that really studying form and making my own selections works best but it is extremely time consuming to do properly. Alternatively one needs to find another factor not generally used by other punters. For several years (about 20 years ago) I had a very good run with place percent before it was well known but it seems to be factored in now along with all the other info.