sentences:  On August 31, González pitched his first career shutout in a 10–0 rout of the St. Louis Cardinals.When González and the Nationals beat the Milwaukee Brewers on September 22, it moved his record to 20–8 and he became the first pitcher in MLB to reach the 20-win mark on the season.He finished the regular season with a major league best 21 wins, to go along with a 2.89 ERA and 207 strikeouts, winning the 2012 Warren Spahn Award as the best left-handed pitcher in the majors.