Nationals-Cubs Preview

The Chicago Cubs are the highest-scoring team in baseball, something that seems like an unfair advantage with the majors' best pitching staff regularly mowing down opponents.

The last time the Cubs' offense was shut down completely also was the last time they lost a game started by Jake Arrieta, who is reinforcing his status as one of the game's top pitchers.

Chicago can win for the 20th straight time with Arrieta on the hill by sweeping a four-game series with the Washington Nationals on Sunday at Wrigley Field.

Cole Hamels, then with Philadelphia, no-hit the Cubs on July 25 with Arrieta giving up three runs in six innings. Not only hasn't Chicago lost with Arrieta (6-0, 0.84 ERA) on the mound in the regular season since, that's also the last time the right-hander didn't post a quality start.

Arrieta is 17-0 with a 0.66 ERA with a pair of no-hitters over the last 19 and is the first Cubs pitcher to win his first six starts in a season since Mordecai Brown won his first 11 in 1908 - the last time the Cubs won the World Series.

He also hasn't allowed more than three runs in 26 straight regular-season starts, joining Chris Short in 1967-68 as the only players to do so since 1913. Arrieta allowed two hits in seven shutout innings to beat Pittsburgh 7-1 on Tuesday.

''You try to enjoy it, but it's short lived because of the goals we have here,'' Arrieta said. ''We play so many games it's smart to get on to the next page.''

The Cubs (23-6) are off to their best start since 1907 and are the first team to win 23 of its first 29 since the Los Angeles Dodgers in 1977 behind a pitching staff that has a 2.53 ERA and an offense averaging 6.2 runs.

They've won six in a row and have scored 21 runs in the first three of this series against a Nationals team that entered with a 2.53 ERA.

Ben Zobrist has four homers and 15 RBIs during a six-game hitting streak after driving in a run Saturday. Kris Bryant homered and Addison Russell had three RBIs in an 8-5 victory for Chicago, which has scored at least five times in each game during its winning streak.

''Everybody participated,'' manager Joe Maddon said. ''I love when everybody takes a piece of the ownership. It really matters within the clubhouse.''

Washington (19-11) has dropped four of five despite averaging 6.4 runs. Ryan Zimmerman drove in two runs while Ben Revere and Stephen Drew had two hits apiece Saturday.

Illinois native Tanner Roark is next in line to try to shut down the Cubs. Roark (2-2, 2.35) is on a solid run of his own, posting a 1.27 ERA while going at least seven innings in each of his last three.

The right-hander was in line for the victory Tuesday at Kansas City before the bullpen surrendered a two-run lead in the ninth of a 7-6 loss.

Roark has a 5.33 ERA in four starts and one relief appearance against the Cubs with Anthony Rizzo going deep twice in their matchups.