After a close win against the Falcons, the Steelers returned home for a game against the Chiefs.  They were facing a WIN AND IN scenario for the playoffs.  They would score first in the first quarter when Shaun Suisham kicked a 23-yard field goal for a 3-0 lead.  The Chiefs managed to tie it up later on in the quarter when Cairo Santos nailed a 35-yard field goal for a 3-3 game.  The Chiefs took the lead in the 2nd quarter when Santos kicked a 25-yard field goal for a 6-3 game.  The Steelers later on in the quarter retook the lead as Le'Veon Bell ran for a 1-yard TD for a halftime score of 10-6.  After the break, the Steelers got back to work in the 3rd quarter as Ben Roethlisberger found Antonio Brown on a 3-yard TD pass for a 17-6 game.  In the 4th quarter, the Chiefs came within 8 when Santos kicked another field goal from 43 yards out for a 17-9 game.  The Steelers however pulled away as Suisham kicked a 20-yard field goal for a 20-9 game.  Santos would later on kick a 23-yard field goal for the eventual final score of 20-12. With the win, the Steelers improved to 10-5 and endured their first playoff appearance since 2011. Antonio Brown finished the game with 122 catches on the season, the third-highest single-season total in league history while Jamaal Charles was held to his second-lowest rushing total of the season.. How many points did the Steelers win by?