Hi Barny,
Don't follow this kind of thing at the moment but there was a thread by punter57, who also started the "Mechanical Longshot" thread, about this very thing so if you look up his posts you should be able to find it.
Unfortunately, blindly following every trainer who decides to lug his horse along way to a meetiing won't work but definitely something to be taken into consideration and there are a lot of winners that pop up at long odds, mid week too.
Also unfortunately, the opposite also happens a lot, a horse trained on the home track gets up, also often at big odds, quite often first uppers.
As there isn't a definite set of rigid rules that will point to the winner it sounds pretty contradictory but with travelled and home track horses it seems definitely worth putting a mark next to their name for future form study and consideration.

I'm sure you're well aware of all this so I'm not trying to teach my grandmother how to suck eggs.

Punter57 seems to no longer post here but while he did he created quite a furore and ruffled a few feathers with his contrarian ideas. He seemed to be very capable and vigorous in his defence of them too .