"Favourites have a bad record"

[slapdash]

Quite often you hear somebody say on the TV racing programmes that in some particular race "favourites have a bad record", suggesting that it's a bad idea to back the favourite. Without having done any research, my gut feeling is that this is probably nonsense. The amount of evidence for any particular race is very small, and most of it quite a long time in the past, so it seems very unlikely to me that any evidence there is is going to be statistically significant. I could believe that some particular kind of race might be known to be bad for favourites, but not a particular race. Any views? Is there any genuine evidence that any particular race is bad for favourites?

[bowles10]

Re: "Favourites have a bad record" slapdash, they make their comments from the trends of that race, e.g you could have a race where the favourite has not won in 15 years! that would probably be unusual, but enough to put the punters off the Fav. The trends have to be bucked sooner or later, but the TV guys are stating fact when they say this.