After struggling more on the road than any other team for most of the season, the Chicago Cubs are enjoying a wave of success away from home.
The Cubs (37-46) started a major league-worst 12-25 on the road before winning six of their last seven. Starlin Castro is batting .423 with 12 RBIS over his last 13 road games, hitting safely in 10 straight. He's also recorded a hit in 12 of his 13 career games at Washington.
Chicago totaled four runs and 12 hits in wins at Boston on Monday and Tuesday, then finished one shy of a season high with 19 hits in Wednesday's 16-9 victory. It was the Cubs' first interleague road sweep since taking three from the White Sox in June 2007.
Justin Ruggiano recorded a career-best five RBIs and was one of four Cubs to homer.
"It's fun to take this series the way we did," said Darwin Barney, who had four hits and was a homer shy of the cycle.
Hammel (7-5, 2.98 ERA) is 7-0 with a 3.12 ERA in nine starts against Washington, winning the last six. He's limited the Nationals to four earned runs over 22 1-3 innings in the last three matchups.
The right-hander gave up two runs over 6 1-3 innings in a 7-2 victory against them last Friday. Hammel, who signed a one-year contract in February, remains the subject of trade speculation with the July 31 deadline approaching.
"I just don't listen to (the rumors)," he told MLB's official website. "I knew what I was getting into coming here. It comes with the territory."
Bryce Harper is 0 for 7 off Hammel and Denard Span is 1 for 13, but Ryan Zimmerman has gone 10 for 28 (.357) with a homer and three doubles.
Washington's Tanner Roark (7-5, 2.98) took the loss opposite Hammel last week, allowing four runs and a career-worst 10 hits over six innings. Nine of those hits were singles.
"They were squaring the ball up and hitting it right through the holes, so you know, there's nothing you can do about it," said Roark, who had allowed five runs in his previous five outings while winning four straight. "I get them again I believe on the Fourth of July, so I'll come back out and go get 'em then."
Roark, who is 4-3 with a 1.59 ERA in eight home starts, won his only other appearance against the Cubs despite allowing two runs in 1 2-3 innings of relief in an 11-6 victory Aug. 21.
This is the first time two starters with identical records and ERAs with at least 15 starts have faced each other since Aug. 15, 1974, when Jim Kaat started for the White Sox against Baltimore's Mike Cuellar. Both pitchers were 13-9 with a 3.54 ERA.
The Nationals (46-38), who are a half-game behind first-place Atlanta in the NL East, have won a season-high five in a row and nine of 12. They're looking for a sixth straight home victory for the first time since starting 6-0 there last season.
Ian Desmond's replay-reviewed home run, his team-leading 15th, put them ahead in a 4-3 home victory over Colorado on Wednesday.
Washington infielder Anthony Rendon is batting .357 during a seven-game hitting streak and was 7 for 16 when these clubs split four games last weekend.
Adam LaRoche homered twice in that series and is hitting .333 with 14 homers and 33 RBIs over his last 38 matchups with Chicago.
Washington has taken 12 of the last 18 meetings.