The Washington Nationals' first four starters have been the key to the club's rise to the top of the NL East.
They're giving Ross Detwiler another chance to join that dazzling group.Detwiler is scheduled to replace the ineffective Chien-Ming Wang in Washington's rotation Sunday for the finale of this three-game Beltway Series with the punchless Baltimore Orioles.The Nationals (41-28) have a major league-best 2.96 ERA, with Stephen Strasburg, Gio Gonzalez, Jordan Zimmermann and Edwin Jackson each under 3.00 individually. Washington's .238 average and 3.8 runs per game both rank near the bottom of the league, so the rotation's success is driving the team's surprising status as division leader."It's unbelievable," manager Davey Johnson said. "It just shows you how good they've been going. I'm impressed, and I'm not easily impressed."Jackson was the latest to turn in a strong performance, beating Baltimore 3-1 on Saturday. That came after Zimmermann's solid outing was squandered in a 2-1 loss in the series opener."That's a good team, and it starts with their starting pitching," Orioles manager Buck Showalter said.The only area of concern in the rotation for the Nationals is the fifth spot. They're going back to Detwiler (4-3, 3.34 ERA) after Wang continued to struggle in Tuesday's 5-4 loss to Tampa Bay, allowing five runs in 3 1/3 innings.Wang is 2/3 with a 6.10 ERA in five games -- four starts -- after opening the season on the disabled list.Detwiler began 2012 at the back end of the rotation, going 3-3 with a 3.88 ERA in nine starts. However, an 8.16 ERA in his last three was reason enough for Johnson to move him to the bullpen.The left-hander was sharp in six relief appearances, posting 7 1/3 hitless innings over his last three outings. He relieved Wang on Tuesday and retired 11 of the 12 batters he faced."He was dominating ... very aggressive after the hitters," Johnson said. "In his last two starts, he was pitching defensively, not attacking the hitters. So I think the stint in the bullpen, if anything, helped him."One of those bad starts came against the Orioles on May 19. He was pounded for six runs and nine hits -- two homers -- in five innings of a 6-5 loss.Detwiler is 0-2 with a 6.75 ERA in three career starts in the Beltway Series, and the Orioles (40-31) may be relieved to face him after totaling six runs and hitting .164 while losing four of five.No. 3 hitter Chris Davis went 0 for 4 again Saturday and is now hitless in his last 28 at-bats, while J.J. Hardy is stuck in a 2-for-31 slump.Wilson Betemit has been one of the few bright spots lately, going 12 for 26 in his last nine games. He has a .418 average in his past 23 meetings with Washington.Jake Arrieta (3-9, 5.83) gets the ball looking to continue the dramatic improvement from his last two starts after going 0-6 with a 9.34 ERA in his previous seven.The right-hander ended that losing streak by posting nine strikeouts in seven innings of a 7-1 win over Pittsburgh on June 13. He lost again five days later, but all the runs he allowed over seven innings came on a grand slam while the Orioles were one-hit by R.A. Dickey in a 5-0 loss to the New York Mets.Arrieta was sharp May 18 against Washington, allowing one run and six hits with nine strikeouts in seven innings of Baltimore's 2-1, 11-inning win. Despite that performance, he's 0-1 with a 7.20 ERA in three career starts against the Nationals.