Rookie Steven Matz is already among the most accomplished hitters of the Mets’ rotation. His RBI double in the sixth inning on Monday night not only extended the Mets’ lead in a 4-2 win over the Dodgers, but also gave him six hits and six RBIs in 12 career starts. Mets starting pitchers have knocked in four runs this season, sixth-most in the National League, and they’ve scored five times.