Interesting answers, in the uk the racing post publishes what it calls a RTF% for each trainer
which indicates the percentage of a trainers runners who have 'run to form' over the past two weeks.
Its based upon each horses expected race rating with its actual rating obtained.
Anecdotally it seems to be worth looking out for.
There's an interesting article about it
here If I had the time, patience and a hefty database
I would investigate using a similar figure for each race.