based off of pop's data from last year 55.6% of all games with a run line of 8 or less went over and 54.9% of all games with a run line of 10.5 or higher went under. assuming 10% juice you could have made a nice profit of 38.6 units last year had you bet accordingly. the one downside in all this being you would have had to make 669 bets.
btw the pivot table for the 2006 mlb master spreadsheet is missing data for 200 games.