Optimism is running high for the New York Giants this year as they begin the first of what will hopefully be many seasons under head coach John Harbaugh. Right now, everyone is feeling pretty good about the team’s free agency activity and recent draft class, including the oddsmakers in Vegas, who, in their earliest of opening odds for each week, have the Giants favored in five games: Tennessee, Arizona, New Orleans, Washington, and Cleveland. In six other games, the Giants, despite being listed as the underdog, have a point spread total of +3 or less, in which the Giants aren’t favored because they’re not the home team. This factor could also suggest that an injury, weather, or some other factor could easily sway the odds back in the Giants’ favor as the game draws closer. Those games include the Week 1 opener against Dallas, Week 5 at Washington, Week 11 vs. Jacksonville, Week 12 at Indianapolis, Week 13 vs. San Francisco, and Week 18 vs. Philadelphia.…