It is no secret how good the Astros starting rotation has done this year. As a team, the Astros have a 2.54 ERA, which is the best in baseball. The Diamondbacks are second with a 2.96 ERA, followed by the Brewers with a 3.20 ERA. In the American League, the Red Sox have a 3.34 team ERA. The Astros and Red Sox are the only two teams in the AL sit in the top six teams in baseball regarding ERA.
That makes sense, because of the designated hitter in the American League. Which makes the Astros team ERA impressive and why the team is 20-10 despite offensive woes at times.