It's officially game week and the first betting lines have opened for this weekend's games. In the world of sports gambling, this first week of games is as much a shot in the dark as anything. While some teams have not made a ton of changes heading into the season, anything is possible when the NFL season starts, which means picking favorites and setting spreads includes some measure of guess work.

The San Francisco 49ers have opened as a 5 1/2 point favorite against the Seattle Seahawks in a matchup of two teams with numerous question marks heading into the season. The home team gets three points just for showing up, so this would indicate oddsmakers like the 49ers in the game, but not by a whole lot. Anything under a touchdown leaves plenty of room for questions.

Injury news can impact a spread, but beyond Michael Crabtree, the only significant injuries are to Reggie Smith and Shawntae Spencer. Crabtree has been working out with the team but we won't know his full status until we start seeing the practice participation reports beginning Wednesday. I don't expect the spread to change too much, but for now I'd think the 49ers to cover is the way to go.