the boookies
Firstly, If the horse wins at the weekend then that horses odds will come down for cheltenham. But is the horses odds determined by how it does at the weekend? I think not, what if it didnt run at the weekend, would the odds still be the same?
Secondly, If you were betting on man utd to win the FA cup and having the bet in a double with them beating whoever they play in the final or any other round along the way, the first part of the bet is dependent on the second part coming in so its conflicting and that bet would not be legal as it would have been taken in error.
In this case we have to ask is the horses odds for cheltenham abosultely dependent on how its going to run on saturday and I think not as they arent guaranteed to change, hence IMHO and in the bookies he has a legal bet.