Braves may lead NL East, but can they sustain extended run of success

After a 4-3 extra-inning win Sunday, the Braves lead the Nationals by 8 ½ games in the National League East.

So why does it seem the Nationals have the advantage as the season’s second half approaches?

It’s because the Nationals have a more reliable rotation.

The Braves have been white-hot during June, but they are doing it with an offense that averages more than seven runs a game.

Teams that win by pounding other teams with runs find that difficult to sustain. On the other hand, the Nationals have more balance with their lineup and pitching.

Both teams play excellent defense. Both teams are trying to fix thin bullpens.

Braves closer Luke Jackson has six of their 13 blown saves. The Nats’ bullpen chaos is well documented.

The Braves are down to four starters after Sunday, when they sent Mike Foltynewicz, an All-Star last season, to Triple-A Gwinnett after he posted a 6.37 ERA.

Foltynewicz missed a chunk of spring training with bone spurs in his elbow. He’s had trouble repeating his delivery. His slider isn’t crisp and he’s giving up a ton of home runs.

He’s been hit for 16 home runs in 59 1/3 innings this season. Last year, he gave up 17 in 183 innings.

“It’s time to press the reset,’’ Braves manager Brian Snitker said.

There are other problems in the Braves rotation.

Former Oriole Kevin Gausman is on the injured list with plantar fasciitis after giving up 17 runs in three starts.

When Gausman returns, the Braves aren’t sure if he’ll be in the bullpen or the rotation, even though his history in Baltimore - and his first season with the Braves last year - is that he pitches well in the second half.

Lefty Sean Newcomb, who had a 3.90 ERA as a starter last season, made four starts before he moved to the bullpen this year. Now he’s sidelined on the concussion injured list.

The rest of the rotation has Julio Teheran (5-5, 3.40 ERA) and newcomer Dallas Keuchel, the lefty that signed for $13 million and made his debut in a Braves loss Friday night at Nationals Park.

Keuchel pitched all right against the Nationals, but he’s rusty. After all, he hadn’t pitched for 265 days, his last start being in the American League Division Series for Houston against Boston in October.

“He’s going to help us a lot the more starts he gets under his belt,’’ Braves catcher Brian McCann told reporters. “The more he gets into the season, he’ll be a little more crisp.’‘

The Braves can’t be sure what to expect from their young starters, Mike Soroka and Max Fried, in the second half. Neither has pitched a full big-league season.

Soroka was hit in the forearm with a pitch Sunday. He left the game for precautionary reasons.

The Braves say neither Fried nor Soroka have innings limits, but they’ll be careful with using them in the second half.

Soroka, 21, who has a late-moving sinker, has been efficient. He’s thrown 89 pitches in seven strong innings against Miami, 93 in seven against St. Louis and 94 in eight versus San Francisco.

In a lopsided win against Pittsburgh, the Braves pulled him after six innings and 68 pitches.

So expect the Braves, with a rich farm system, to be in the market for another starter and a reliever before the July 31 trade deadline.

They’ve already said they were hoping to get both Keuchel and another late-signing free agent, closer Craig Kimbrel, who signed with the Cubs.

The Braves might target San Francisco starter Madison Bumgarner and reliever Will Smith in the same trade.

The Yankees, leaders in the AL East, are interested in Bumgarner and the Twins, leading the AL Central, are interested in both, especially Smith.

Bumgarner is a free agent after the season, and given his North Carolina roots, the Braves think they have a chance to sign him to a long-term.

The Nationals, of course, have Max Scherzer, Stephen Strasburg, Patrick Corbin and Aníbal Sánchez in the first four slots of their rotation, each battle-tested in second-half runs.

The Phillies are fading, losing nine of their last 10 games.

Andrew McCutchen, their leadoff hitter, is out for the season. They have struggled to score runs since he was sidelined in early June.

The Phillies bullpen has been thinned by injuries and their rotation has underperformed, especially Jake Arrieta and Aaron Nola.

In fact, none of Philadelphia’s new players has done well.

Shortstop Jean Segura slumped in June. Ex-Nat Bryce Harper is on a pace for 200 strikeouts. And catcher J.T. Realmuto hasn’t lived up to expectations with his bat. Reliever David Robertson has been injured and not thrown a pitch.

The Braves’ biggest challenger in the division will probably be the Nationals.

They play each other 14 more games, seven in July, seven in September.

For now, Atlanta leads in the standings.

But the Nationals have the better rotation and the most stable closer.