Answer based on context:

 The Falcons returned home to take on the last of their AFC Opponents. Coming back home they are 3-0 against the AFC West. However, for the 3rd straight week, the team would trail a game as the Raiders moved ahead after Sebastian Janikowski's 53-yard field goal for the only score of the first quarter. The Falcons however took the lead with Matt Ryan finding Roddy White on a 4-yard pass to move up 7-3. However, the Raiders would come within a point with Janikowski kicking a 22-yard field goal and then retook the lead with Carson Palmer's 25-yard touchdown pass to Denarius Moore for a 13-7 halftime lead. After the break, the Falcons were able to score 13 unanswered points. First, Bryant kicked 2 field goals from 41 and 20 yards tie the game at 13-13. Then, In the fourth quarter, they took the lead after Asante Samuel returned an interception from 79 yards out for a touchdown to make the score 20-13. The Raiders however were able to make up for this mistake as Carson Palmer drove them down the field and Darren McFadden ran a touchdown in from 2 yards out to tie the game at 20-20. However, again the Falcons were able to complete the comeback as Bryant nailed a 55-yard field goal with 0:01 left to make the final score 23-20 With the win, the Falcons go into their bye week with their first ever 6-0 start to a season. They also finish the season 4-0 against the AFC West and with the Texans' loss to the Packers on Sunday Night, they remain the NFL's only undefeated team.

How many points were the Raiders winning by at halftime?
6