This is an interesting subject, if your talking about "form" or "recency" .

Neither of which I believe, other than they both are an artifact caused by the grading ladder or the physical features of the track.

But on your knowing which races to select, if you flip what your doing over, look at the in-form dogs (tale a look at the form of the fav in race 12 Sale you'll find it would be in-form solely on drawing the 1-8 box 50% of the time in its last 8 starts.
seeing it wasn't the top raw speed dog, this produced an edge