With Tanner Roark and the rest of the Nationals’ pitching staff quieting opponents on a consistent basis, and with the lineup on the verge of being injury-free, we’re about to see what Washington is capable of at full strength. (Mitchell Layton/Getty Images)

What if, for the rest of the summer, Washington just enjoyed its baseball?

In the past two days, with back-to-back wins over the nemesis Braves by their supposed fourth and fifth starters, the Nationals raised the possibility that the slasher-movie portion of their season, when fans grip the sides of their seats in fear wondering when the next Nats player will break a bone or snap a ligament, has come to an end. The wake-up-screaming nightmares of Atlanta hexes may also be ending. Soon, the pleasures of a full and talented roster — and not a Braves jinx in sight — may be on view.

On Sunday afternoon in a 4-1 win, Tanner Roark and the best ERA bullpen in baseball finished what Doug Fister began on Saturday night in his 3-0 victory — a two-day shutdown of the Braves. Washington not only split a four-game series to maintain its 11 / 2-game lead in the National League East. The Nats probably extinguished a Braves whammy and shifted the feeling of an entire section of their season. Atlanta will always be tough. But that’s far different than being invincible.

With catcher Wilson Ramos coming off the disabled list on Thursday and Bryce Harper the following week, perhaps the Nats can soon simply play baseball. That process has already begun. The Nats are on a 14-8 run in which they’ve stomped foes by a combined score of 97-58. Their pitching ranks in the top three in every category that matters and is better than it was in 2012. Instead of wondering how to compensate for 219 lost games of injuries to major players, the Nats may find out what they can accomplish.

What would that be? “I don’t know,” Ryan Zimmerman said. “But I sure hope we get to find out.”

Since Fister was on the disabled list before the season began and Ramos broke his wrist on opening day, rookie Manager Matt Williams has never had all of his core players for even one inning. What’d that be like? “I will knock on wood,” said Williams, knocking on a table and grinning, “and decline to answer.”

Baseball seasons are famously long, yet plot lines shift so dramatically. On Friday night, Anthony Rendon hit a two-run homer with two outs in the ninth off Braves superstar closer Craig Kimbrel on a 98-mph fastball. Nationals Park set its decibel mark for 2014. Surely, that was the end of the Braves’ one-sided head-to-head dominance since the beginning of last season. But it wasn’t. Atlanta won in the 13th inning, then came back with its ace in Julio Teheran on Saturday.

Enter Fister. If we’ve just seen a turning point — and these past two days walk, talk and wave their arms like one — the man who flipped the script with eight scoreless innings was the bursting-with-energy 6-foot-8 right-hander. “We don’t have No. 4 and No. 5 starters,” said reliever Tyler Clippard, chuckling. “We don’t have anybody worse than No. 2. And I’m not saying who I think that is.”

On Sunday, Roark (7-4, 2.79) battled out of jams in the fourth and fifth innings after ump Mark Carlson missed what Pitchf/x showed were totally inside-the-zone inning-ending third strikes. (If this is the age of replay, then let’s tell the truth.) Roark needed 19 extra pitches to end innings that might already have been finished. Such it’s-part-of-the-game mishaps are exactly what derailed Roark’s career — until ’12 when he finally stopped seeing bad breaks or obstacles and decided “my job is ‘Just pitch.’ ”

For the 11th time in 20 career starts, Roark allowed one run or less. They don’t make No. 5’s like that.

“After the way we came back against Kimbrel to tie it Friday, you’re thinking, ‘This is where it changes.’ But it didn’t,” Clippard said. “We never lost confidence. The way we came back to win the last two games shows a lot about who we are.”

If the Braves don’t own the Nats, if they aren’t their daddies or even their big brothers, how bad can the Nats’ world look? By Sunday evening a case could be made that the Braves, who are in a 10-16 slump and lost starter Gavin Floyd to a broken elbow on Thursday, are the ones with head issues.

Rendon’s homer off Kimbrel didn’t produce a win, but it dented a key piece of the Braves’ psychological armor. On Saturday, Teheran melted down, balking after repeatedly shaking off signals from catcher Evan Gattis. The pair had a counseling session between innings.

On Sunday, Braves starter Ervin Santana threw a 95-mph fastball directly at Rendon’s head on the first pitch of his first at-bat. A message since Rendon tore up the Braves the entire series? Since Bobby Cox retired, some Nats believe such accidental pitches have become part of the Braves’ DNA under Fredi Gonzalez. They responded with a Rendon walk, singles by Jayson Werth and Adam LaRoche and a Zimmerman sacrifice fly for a two-run lead.

By the late innings Sunday, Chris Johnson and Justin Upton were ejected after waving their arms and pointing at umps after strikeouts. That’s the kind of snapping that foes love to watch.

The Nats aren’t in the Braves’ heads yet, but it could happen by the next time they meet in seven weeks. Without Kris Medlen, Brandon Beachy, Tim Hudson and Paul Maholm from last year’s rotation, minus Floyd who was added this season, the Braves’ pitching can no longer overcome their next-to-worst offense in baseball. If they can’t dominate the Nats head-to-head, then what?

Only wins and losses count, but by midseason run differential is wonderfully predictive. The Nats are outscoring foes at the pace of a 91-71 team while the Braves project like a 78-84 squad. And the Nats have built that margin with a total of only four home runs all season from the much-injured trio of Zimmerman, Harper and Ramos who, by this time, might normally have 30.

“Who Are the Nats?” is a question with levels. One answer just arrived. The Nats aren’t mysteriously “owned” by the Braves to the point where that factor alone dooms their division chances.

Now, other questions can be asked — ones that make a summer entertaining and fascinating, not just creepy questions about hexes. Perhaps the biggest question looms just days ahead. How good could the Nats be if they actually put all, or even almost all of their team on the field at the same time?

For more by Thomas Boswell, visit washingtonpost.com/boswell.