I have few times tried to explain what I do, but it is very hard to do so.
Here is a classic example of what I look for.
This is my one and only bet for the day.

Wagga R2

Bookie sites had Instructed as the fav and it remained the fav throughout the betting, at around $3.5
My Marwina was the 3rd fav at $4.6, it was $6.0 something on nswtab and $8.0 something on unitab.
Getting around the last 3 mins it came on sky that the only one they???? wanted to back was My Marwina, so what happens all the SHEEP back My Marwina and Instructed blew out.
Instructed went from middle 3's to middle 4's on the tab, My Marwina went from 6's to middle 3's
When I put my bet on as they were going into the barrier Instructed was showing $2.5 for the place.
$3.6 win books and $2.5 place tab,now surely none of you can say that is not good value.
Instucted finished paying $4.6 win and $2.1 place on nswtab, and $3.6 win and $1.5 place on books.
The way I read the race was a reasonable amount of money was put on My Marwina to start the SHEEP following so that Instructed would blow out.
It is worth it for certain people to WASTE money on a horse to let the odds on their selection blow out.
Instructed paid $2.1 so thats $440 for the day.
This is the way I try to read odds, it doesn't always work BUT I will guarantee I
have LESS losing days than having a 10 year database and or doing the form everyday.

Cheers