correct me if i'm wrong but the % numbers on sportsbook spy are determined by the % number of tickets on a team, so in this case 63% of tickets are on the saints, but the when the line moves down in this case on the falcons to +2.5, that means that more money is being placed on the falcons. In this example we can hypothesize that the big bettors in vegas, or the professionals, are on the falcons. they make up a smaller % of total tickets but account for a majority of the money and risk to the book, so they are the ones moving the line.