What is the three-point home field advantage in the NFL?

Oddsmakers, when figuring their point spreads, usually give the home team three points. There are some oddsmakers, and depending on the team will only grant two, or two-and-a-half points. What that means in real terms is let’s say the New York Giants are at home against the Tampa Bay Buccaneers. Oddsmakers might feel those two teams are very equal in talent and have similar accomplishments thus far on the field. But because the New York Giants are the home team they will make the Giants -3 and the Tampa Bay Buccanners + 3. If that same game the same week was being played in Tampa Bay, the Tampa Bay Buccaneers would be – 3 and the New York Giants would have been + 3.