ESPN.com's group of NFL Insiders offer an in-depth free agency grade for all 32 teams. The San Francisco 49ers received a B- grade.The 49ers concentrated mostly on keeping their own free agents as in-house priorities. However, former Colts' general manager Bill Polian said the team's addition of safety Antoine Bethea was a "home run." Polian drafted Bethea to the Colts.In other 49ers' notes:Sports illustrated heaps praise on 49ers' general manager Trent Baalke.