(if a horse is 66/1 into 12/1 you know its probably worth a small bet!)
In the spirit of panto Lee:
Oh no it isn’t!
If a horse is backed from 66/1 down to 12/1, you know it was probably value when it was 66/1.
You also should know that it is probably NOT worth a small bet at 12/1.
(Reet is going to love me saying this ).
Any 66/1 shot is value if the punter believes it to have a better than 1.5% chance of winning. Any 12/1 shot is value if the punter believes it has a better than 7.7% chance of winning. It is highly unlikely a horse first offered at 66/1 is still value at 12/1. Especially when bookmakers have to offer a shorter price than they would normally, because of liabilities from the gamble.
Bookmakers love punters who follow the money, as they know anyone doing so (the vast majority of time) is taking poor value. Therefore won’t make an over all profit.
Best to either: Identify the good value bet at 66/1 before it is backed, or back something else against the "gamble". With one shortening dramatically, there’s every chance something has gone out to a value price.
Apart from – the odd occasion when a small market move is a positive sign of a horse who’s out of form might be coming back to form. (Though no more than a "positive sign"). – Following money is a waste of time.
Value Is Everything