(AP Photo/Alex Brandon)

The Washington Nationals beat the Milwaukee Brewers last night behind a solid outing by Gio Gonzalez. And, as Boswell wrote, the Nats may have exorcised the demons of Atlanta.

Only wins and losses count, but by midseason run differential is wonderfully predictive. The Nats are outscoring foes at the pace of a 91-71 team while the Braves project like a 78-84 squad. And the Nats have built that margin with a total of only four home runs all season from the much-injured trio of Zimmerman, Harper and Ramos who, by this time, might normally have 30.

But here is the thing: this Nats squad is not producing against the top teams in the league. Sure, the pitching has been good, but Washington’s bats have gone largely silent when playing the better teams.

For example, when facing off against an opponent with a winning percentage lower than .500 the Nationals have posted a .778 OPS, which is good. Against those teams who win more than half their games that number plummets to .643. That’s bad. If that held, it would be among the lowest we have seen in years.

Since 2006, teams have posted a .687 OPS against the winning teams en route to winning  the NL East and so far only the Miami Marlins, who are 2.5 games behind Washington for the division lead, fit the bill (.764).

A healthy Harper will help (.828 OPS vs. team with a winning percentage over .500 since 2013), but Zimmerman (.596) and Ramos (.655) shouldn’t be counted on for much.

We can quibble about the small sample sizes of these numbers, but one thing is not up for debate: if the Nats want to be playing baseball this postseason they need to show their hitting can be every bit as good as their pitching. Especially against the teams they will likely be facing in the playoffs.