I am no statistician, but I was pretty sure that was wrong, so I tested it.
The results of laying at BSP to a risk of 1 point per horse with zero commission for all runners in 2017 are as follows:
The results when you assign each horse a random percentage chance between 1% and 99% are as follows:
I would therefore conclude that BSP beats randomness.
I once read a mathematical explanation of the wisdom of the crowds. The maths went over my head, but the principle was that, the more people independently arrive at an estimation of something, the more accurate it's likely to be as they more perspectives are brought to bear (which is a good argument for the jury system and democracy, incidentally). One person may overestimate the effect of a 9lbs extra weight, but if someone else underestimates it by the same amount, in theory they cancel each other out.
I imagine that all sorts of things move the markets - bookies hedging their bets, traders, syndicates, spoofers, you name it - which may account for a lot of the volatility. How markets can go from jumping all over the place to being spookily accurate, I don't know.
Maybe what happens is that, once the market moves into value lay or back territory, value backers or layers push it into accurate price territory until there is no more value to be had (because the price is near as dammit spot on).
Derek27 wrote: ↑
Sat Jan 27, 2018 3:51 am
According to the laws of probability, if you gave each horse a random price, as long as the overround is 100%, you should break even backing or laying any particular number.