We're about halfway through the 2012 NFL season, which means it's time for teams to check their midterm grades.
Overall, the San Francisco 49ers have to be pleased with their report cards after seven games. They've played stingy defense and featured a bulldozing running game, both of which were on full display in a win against the Seattle Seahawks on Thursday Night Football that put San Francisco in sole possession of first place in the NFC West.
But not every positional unit has performed up to expectations.
The following slides present grades for San Francisco's positional units.
Note: Grades are based on how each unit is performing in comparison to other teams' units. For example, San Francisco's quarterbacks have had their struggles, but they'd receive a higher grade than Arizona's quarterbacks for having better stats, a better record, etc.