Eastern Central Western
Atlanta .492 Cincinnati .544 Colorado .523
Philadelphia .482 Milwaukee .520 Arizona .517
Miami .472 Chicago .508 San Francisco .517
Washington .458 St. Louis .504 Los Angeles .499
New York .443 Pittsburgh .496 San Diego .495
The Pirates now face the easiest schedule in their division over the rest of the season. It's not a huge difference--maybe a game easier than the Cubs and Cardinals over the remaining 45-46 games--but it's no longer a detriment.
And if you're wondering why the NL East teams have it so easy, it's because the division has only one team above .500 (the Mets, and their record's worse than five other teams in the league) and has the league's worst (Phillies), second-worst (Marlins), and sixth-worst (Braves) teams. They benefit from playing each other a lot.
Record Against Winning Teams: We heard some fretting earlier in the season about the Pirates' seeming inability to beat teams with winning records. I wrote about it in June. I wrote about it . Generally, teams that do well against teams with winning records, as opposed to just beating up on weak teams, do better in the postseason, when all the games are against good teams. Last year, for example, the Angels had the best regular-season record in the American League, and the Nationals and Dodgers were 1-2 in the National League. Each was bounced from the postseason in the Divisional Series. (Then again, the World Champion Giants had the third-worst record against winning teams in last year's postseason, so this isn't a hard and fast rule.)
To date, the Pirates are 26-18 against teams playing .500 or better ball. That's the third best record in the National League (the Cardinals are 31-19, the Cubs are barely ahead at 27-18) and the fourth best in the majors (the Blue Jays are 33-23). In addition, Pittsburgh's one of only four National League teams (the other's the 18-17 Giants) with a winning record against clubs that are .500 or above. So you can worry about rotation depth, Starling Marte's health, and first base, but you shouldn't worry about the Pirates' ability to compete with good teams.