FanPost Friday: Who, or what, is the X-Factor?

Photo by Maddie Meyer/Getty Images This was my choice on the preview podcastThe Red Sox are somehow one of two teams left standing in the American League, with only the Astros standing in their way of a pennant and a chance at a World Series championship. Every series at this point in the season is, of course, going to be difficult, but the Astros in particular are a tough matchup. These two teams met twice in the first half when the Red Sox were playing about as well as they had all season, but Houston handled those games easily. Both teams are different now, but those performances certainly loom in most of our memories.

With that in mind, the Red Sox are going to need some big…