The Vikings scored first, and quickly. After the Lions failed on a field goal attempt when new punter/holder Sam Martin fumbled the snap, the Vikings took over on their own 22. On the first play from scrimmage, Adrian Peterson scampered 78 yards for a touchdown. David Akers made it 7-3 on a 33-yard field goal, though the Lions missed out on seven points that series when a touchdown reception by Calvin Johnson was reversed. In the second quarter, Akers connected on a 42-yard field goal to make the score 7-6. The Vikings responded with a 65-yard touchdown drive, capped by a 4-yard TD run from Peterson, to go up 14-6. The Lions closed the gap late in the half when Joique Bell finished off a 70-yard drive with a 1-yard run to make it 14-13. Bell plunged over from the 1-yard line again in the third quarter to put the Lions up for the first time in the game, 20-14. The Vikings' Blair Walsh narrowed the lead to 20-17 with a 52-yard field goal. The Lions then went up 27-17 when Matthew Stafford and new acquisition Reggie Bush connected on a 77-yard pass play. Adrian Peterson scored his third touchdown of the day, on a 4-yard pass from Christian Ponder, to put the Vikings within 3 points again, 27-24. The Lions would get the only score of the fourth quarter, a 1-yard touchdown pass from Stafford to rookie tight end Joseph Fauria, making the final score Detroit 34, Minnesota 24. Reggie Bush had 191 yards from scrimmage on the afternoon (90 rushing, 101 receiving), while Matthew Stafford was 28-of-43 passing for 357 yards, two touchdowns and one interception. After Adrian Peterson's opening 78-yard run, the Lions defense held him to just 15 yards on 17 carries.
Question: How many incomplete passes did Stafford throw?
Answer: 15