After battling the Super Bowl champions in Week 9, the winless Raiders went back home for Week 10 to take on their divisional rival and the defending AFC Champion Denver Broncos for the first time all year. Broncos QB Peyton Manning was immediately picked off by cornerback D.J. Hayden on his second pass of the game 30 seconds in. Taking over near midfield, the Raiders got down to the Denver 23, but were forced to kick a 41-yard field goal, which Janikowski was successful on. Broncos kicker Brandon McManus responded with a field goal of his own, and the game was tied at 3 apiece. In the second quarter, McManus added another field goal and, later in the period, the Raiders intercepted Manning again; this time, it was Justin Tuck. Oakland scored a touchdown off the turnover and took a 10-6 lead on a Derek Carr 5-yard touchdown pass to wide receiver Brice Butler. However, after 2 unsuccessful drives for each team, Carr was  intercepted by Denver cornerback Bradley Roby and the Broncos stormed back with two quick touchdowns. Both touchdowns were passes by Manning to C.J. Anderson and Emmanuel Sanders of 51 and 32 yards, respectively. Denver led 20-10 at the half. In the second half, Oakland's offensive miscues continued as Khalif Barnes fumbled at his own 13-yard line, and the Broncos wasted no time as Manning's 10-yard pass to Julius Thomas put Denver up by 17. Oakland's next possession ended in a punt, and Manning went right back to Thomas for another touchdown, Peyton's fourth of the day and second from 32 yards out. Carr was picked off again, the Broncos scored yet another touchdown on Manning's fifth of the game and second to Emmanuel Sanders, and the visitors took a commanding 41-10 lead. Down 31 points, the Raiders headed into the 4th quarter getting embarrassed by the potent Denver offense, and were unable to do much more than score an insignificant touchdown with 53 seconds left. The Broncos left Oakland with a 41-17 win and moved to 7-2 on the season. Meanwhile, the Raiders' woes continued as their record fell to 0-9.
Answer this question: How many points was Denver ahead by at the half?
10