Of all the major sports, baseball is known for not having a great home field advantage. During the regular season, astute bettors will prey upon bookies by betting on teams that are in situations where the home field advantage is extreme.
Home teams win on average 53.6% of the time. This translates to a 7.2% advantage over road teams which is a smaller disparity compared to Basketball and Football.
Home teams in Football and Basketball feed off of their home town fans and are motivated. With baseball, it is most appropriate to try to find situations in which baseball teams will be more motivated.
Consider the Red Sox are 51-15 + 29 units the past 3 seasons at home off a home loss. Over the same span and angle, the Rangers are 47-33 +17 units and the Braves are 52-20 +20 units. These are 3 such teams that have a strong home field advantage given this situation. Because baseball is such an unpopular sport with bettors and this angle does not apply to all teams, the oddsmakers have not had to adjust on a situation as this.
Those 3 teams alone combined for 150-68, +66 units. This means that to even it out, the spread would have to be adjusted 30 points. So instead of being -130, the team would have to be -160. Instead of being +145, they would have to be +115. This is considerable in the eyes of most bettors. The normal home field advantage is already taken into account in the spread but it is the handicapper