(Alex Brandon /AP)

Tanner Roark walked into the Nationals’ dugout Tuesday night after the seventh inning. Manager Davey Johnson shook his hand and told him his night had ended. Roark had allowed two hits and one walk over seven scoreless innings. His pitch count sat at 101, 23 more than he had thrown in any big league appearance. He looked at Johnson and asked, “You sure I’m through?”

“Yeah, you’re through,” Johnson said, laughing as he turned and walked away.

Roark had reached his limit, but who could blame him for wanting to keep pitching? Since his promotion Aug. 7, Roark has turned from call-up to sensation. In the Nationals’ 4-0 victory, Roark pitched all night with a 1-0 lead and the Braves never threatened. He improved his record to 7-0 and lowered his ERA to 1.08 after 41 2/3 major league innings.

“It’s not smoke and mirrors right now,” first baseman Adam LaRoche said. “You get guys coming down to first and talking about how good his stuff is, some really good hitters that are praising him. It says a lot. There’s not a lot of comfortable at-bats against him. It’s quick strikes and, again, he’s locating down so he’s getting a lot of chases down.”

Roark has never been regarded as a star or a significant prospect. In 2008, the Rangers drafted him in the 25th round. The Nationals acquired him and another minor league pitcher for Cristian Guzman at the 2010 trade deadline. Last winter, the Nationals left Roark unprotected from the Rule 5 draft for the second straight year. They invited him to major league spring training this year, and shipped him out in the first round of cuts.

And now here he is, a crucial cog in the Nationals’ push toward the second wild-card spot. The Nationals have won all three of his starts, and counting his tenure as a long reliever the Nationals have gone 10-2 in games he’s pitched.

How? Roark’s ascension began last season, when he told himself he would not allow his temper to control him on the mound. He would not the things out of his control – fluky hits, errors, whatever – distract him. He would throw strikes. He would be confident. He would attack, above all else.

“I feel that last year is when I had my, I guess, mental turnaround,” Roark said. “That was the biggest thing for me.”

On the mound, Roark has succeeded with his ability to keep hitters off-balance with precise control. Manager Davey Johnson raved about Roark’s skill as a pitcher, a quality that, to him, made his strong big league start more than a fluke.

“Well it’s been impressive, but it doesn’t take long when you see a guy who knows how to pitch,” Johnson said. “He made quality pitches all night to good hitters. I don’t think anything was hardly hit hard. I was comparing him with Taylor Jordan and telling [pitching coach Steve McCatty], ‘Taylor Jordan’s got maybe the harder fastball, good change-up, scouts will like him over Tanner.’ But I said I’ve got to put Tanner ahead of him, because of great command. Composure, poise out there is unbelievable. And he competes.”

Johnson compared Roark in passing to Greg Maddux, which should never happen because no pitcher is or will ever be Greg Maddux except for Greg Maddux. But that gives some idea of how Roark has succeeded. He’s not all smarts – his fastballs sits between 91 and 94 mph, and it has good sinker. But he relies on command and intelligence.

“He’s got great command,” Johnson said. “Ever since he’s been here, whether it’s out of the ‘pen or starting, it’s been quality. I mean, I can’t say enough about location. Everybody’s all wrapped up in the velocity.”

Tuesday night, Roark focused down in the strike zone. He almost always got ahead of hitters, but when he fell behind he mixed in curves and sliders in fastball counts.

“He wasn’t missing any pitches over the plate,” Braves catcher Gerald Laird said. “When he was going away, he was throwing that little two-seamer backdoor and it was coming in on your hands. Then he had that little slider working.  Tonight, it seemed like he was hitting his spots and wasn’t making any mistakes.”

He struck out six Braves, throwing strikes relentlessly and then getting hitters to chase pitches out of the zone with two strikes. He stayed a step ahead of hitters by reading their swings. Take his encounters with Freddie Freeman as an example.

Roark knew Freeman’s swing works best when he extends his arms. He got him out in the first inning when he threw an outside curveball and Freeman lined out to third. In third, he wanted to come in on Freeman. Even though his sinkers weren’t on the corner, he was able to jam Freeman enough that his flyball to center died well short of the track.

“I’m just going after people and recognizing their swing paths – not their swing paths, but what they swing at and how they react to certain pitches. That’s what I base each pitch off.”

In the sixth inning, Roark moved back to outside. Rather than peppering the strike zone, Roark worked the outer edges, moving the ball farther and farther off the plate until Freeman whiffed at a change-up that nearly hit the plate. Against one of the best hitters in the league, Roark managed to dictate every at-bat, maintaining his aggression but switching his means.

“He’s doing unbelievable,” Denard Span said. “Every time he’s been called to pitch he’s done a good job. He’s done more than what we’ve asked of him actually. I’ve been very impressed just watching him pitch and go to work. In center field I can see he’s fooling a lot of hitters.”

Roark surely will not sustain a 1.08 ERA. But he has already become a candidate to join the Nationals’ rotation next season. Johnson acknowledged it won’t be his decision, but he gave Roark an endorsement for the 2014 rotation. All the signs so far suggest Roark is not through yet.