When Edwin Jackson staggered off the mound in the middle of the fourth inning today, he wondered how his day had unraveled so fast. He began his fifth spring training start exactly to plan, pumping strikes and letting Orioles hitters put the ball in play. He shrugged off soft singles.

“I started off doing exactly what I wanted to do,” Jackson said.

But as the Nationals extended their winless streak to 11 games, the result turned ugly. Jackson allowed 10 runs, seven earned, over 3 2/3 innings after the Orioles scored five runs in the fourth inning, which included Jackson walking in a run with the bases loaded. Jackson’s start upped his ERA this spring to 6.88, and he has yielded 11 earned runs in his last 7 2/3 innings.

Still, Jackson remained resolute. With two starts remaining, he had no concern about preparing for this season, his first with the Nationals.

“I have a lot of confidence in myself,” Jackson said. “When we start playing, I’ll be ready to go for sure. It’s always good to go out and be lights-out in spring training. Sometimes, it doesn’t happen like that.”

Jackson drew some of the confidence from his past. He had bad spring trainings the past two seasons, posting a 5.32 spring ERA in 2010 and 5.59 in 2011.

“Games like this don’t affect my confidence,” Jackson said. “When we get ready to play, I’ll have just as much confidence in myself. I’ll be ready.”

Jackson started strong, throwing a biting slider that the Orioles whiffed at several times. He struck out four batters in his first 3 1/3 innings. In the fourth, though, he began leaving fastballs up in the zone. He thought the Orioles had hit good pitches before the fourth, even Matt Wieters’s three-run, wind-aided homer to left.

In the fourth, though, he missed location. He issued consecutive walks, one to load the bases and one to force in a run. Jackson felt he allowed the game to spiral.

“My main thing is just controlling situations, when things start to speed up not speeding up with them,” Jackson said. “Just slow it down and control the game.”

Said Manager Davey Johnson: “I like the way he was throwing. Obviously, he wasn’t hitting his spots. His location wasn’t very good at all. He got his work in. Not the way you want it in, but he got it in.”

Jackson could at least find comfort in knowing he had company. His ragged start made him the latest Nationals starters to turn in a crooked line score. Starting Thursday, when Gio Gonzalez allowed eight earn runs in 3 2/3 innings, Nationals starters have allowed 19 earned runs in 12 1/3 innings, a 13.86 ERA.

Johnson found solace in their collective stamina.

“I like where they’re all at,” Johnson said. “That’s the only thing you worry about in spring training, arm strength and what kind of shape they’re in. I’m comfortable with all of them.”

The Nationals’ pitching has only made the team’s offensive woes more acute. The Orioles out-hit them, 17-4, and the Nationals dropped to 0-10-1 since March 13. Johnson expects the Nationals will improve Sunday, once their three-day road swing ends and he begins using his everyday lineup.

“I get tired of getting up whupped up on,” Johnson said. “This coming week should be a whole lot different.

“It’s been kind of a grueling three days. My guys competing for spots on the ball club, they’ve played more this spring than every day players. They’re dragging, too. It will be good to get them a little bit of breathing room.”