Hi Max,
One very strong filter to consider is...

.Only Target races where the whole field has had 2+ career starts .
Otherwise, delete the race.

The reason for this is to be able to compare apples with apples,
instead of apples with apple surprise.
Just look at the outsiders that get up in those scattered form races, so they are usually best left alone.

There is nothing wrong with Maiden races , so long as they meet above criteria.

__________________
Cheers.