I would think any regular handicapper keeps his own power ratings and makes spreads before looking at the opening line. He then compares his own spreads with those of the opening line looking for discrepancies and the accompaning value and bets those in which his numbers have the upper hand. If you ask most regular cappers what the opening lines are going to be for next weeks NFL games, most can give you the spread off the top of their heads with maybe half a point to 2 point differences.
I don't keep a record of my initial prices, I just keep my power ratings. My success or setbacks at betting the discrepencies tell me whether my numbers are solid or need tweeking. We all weigh our variables differently hoping to come up with a winning formula.
