The San Francisco 49ers run defense, which ranks last in the league, has broken a franchise record for rushing yards allowed in a season. The previous record, set in 1978, was 2,363 yards. So far this season, the 49ers have allowed 2,365 yards this season and they still have a quarter and a half to play against the Atlanta Falcons, who lead the league in scoring.

The 49ers currently trail the Falcons 31-13 at the Georgia Dome. Defensive coordinator Jim O'Neil has been criticized for much of the season as his unit has been playing very poorly against the run. The 49ers defense has allowed over 100 yards rushing in 11 of their 14 games – including against the Falcons – so far this season.