In the 2015 season opener, the Houston Texans took on the Kansas City Chiefs with Brian Hoyer in his first regular season start as the Texans' quarterback. Hoyer's first pass was intercepted which eventually lead to a Kansas City touchdown. The Chiefs managed to score another 7 points off of turnovers to take a 14-0 lead with 4:28 left in the first. Houston finally managed to get on the board late in the 1st quarter following a 4-yard pass to DeAndre Hopkins from Hoyer. With Randy Bullock missing the extra point the Texans trailed 14-6 with 0:46 left in the 1st. Following another dismal quarter for the Texans, Kansas City lead 27-9 at halftime. Houston managed to shut out the Chiefs for the entire second half and with almost 6 minutes left in the game brought Ryan Mallett in as quarterback, who led the team on two scoring drives. Nonetheless the Texans couldn't manage a comeback and fell to the Chiefs 27-20. This is the first time since 2009 where the Texans lost their season opener. Houston kicker Randy Bullock became the first player to miss a point-after attempt following a rule change for the 2015 season, which requires the ball to be snapped from the 15-yard line.
Question: How many points was Kansas City ahead by at halftime?
Answer: 18