It is a statistically proven fact that the first five in the market will win roughly 80% of all races.It makes no difference what market that is.....teletex,Tab,prepost or bookies,those figures will stand up.So how can anyone deem whether any of same are effecient,or not?Again,does it not boil down to opinion?If you can back your own opinion V market opinion and get it right on a regular basis,would you not have a winning edge?Personally,there is an angle I have had a lot of success with using the dreaded prepost market.Any race you consider bettable look at the horses on the first 5 LINES of betting....IGNORE the prices.Do the form study for all horses on those lines,which includes equals etc.If you have the knowledge and the skill to study the form,isolate your 2 main chances,and then look at their prices.If prices permit,I Dutch both,or in certain case I will back one and save on the other.Try it...you may just surprise yourself.