Phillies-Braves series: Three things to know about NL East showdown with season-series tiebreaker on the line

The Philadelphia Phillies and Atlanta Braves will begin a pivotal four-game series on Thursday night that will help determine the National League East. The Phillies, the host, enter Thursday's contest with a five-game lead in the division. Anything short of a Braves sweep or series win will leave them five-plus back with less than a month of regular season remaining, putting the Phillies very much in charge.

With a series of such magnitude on the horizon, we here at CBS Sports figured we'd spotlight a few things worth knowing heading into the series opener. First, though, let's provide some pertinent viewing information about the Phillies-Braves series:

• Thursday (6:40 pm ET) : RHP Charlie Morton (ATL) vs. LHP Cristopher Sánchez (PHI)
• Friday (6:40 pm ET) : RHP Reynaldo López (ATL) vs. LHP Ranger Suárez (PHI)
• Saturday (7:15 pm ET) : LHP Max Fried (ATL) vs. RHP Zack Wheeler (PHI)
• Sunday (7:10 pm ET) : RHP Spencer Schwellenbach (ATL) vs. Aaron Nola (PHI)

Now, onto the things you need to know.

1. Phillies have started to course-correct

You may recall that the Phillies had encountered some turbulence earlier this month . Although they're still under .500 since the start of July (23-26), they've shown signs of improvement as of late. Indeed, the Phillies enter Thursday's game having won four of their last five games, including series victories against the Houston Astros and Kansas City Royals -- two potential World Series foes should the Phillies go that far.

Star first baseman Bryce Harper has also started to recover from a career-worst stretch. That's no exaggeration, either. He batted .149/.240/.358 in July, with his .598 OPS standing out as the lowest of any month in his career in which he received 50 or more plate appearances. Harper has an .803 OPS in August; that's not up to his usual par, but a lot closer to it than the marks he was posting around this time last month.

Despite Harper and the Phillies' scuffles, they haven't seen their lead reduced by much. They entered August with a 6 1/2-game edge. We'll see where things stand after this series, but it's fair to write that they're in a good spot.

2. Braves in position to clinch tiebreaker

One notable subplot from this weekend's set concerns the state of the season series. When Major League Baseball expanded the postseason, it did away with tiebreaker games. That means that there's more emphasis than before on winning the head-to-head matchup against your division foes, since that's the first tiebreaker.

In this case, the Braves enter Thursday having won six of their nine games against the Phillies to date. This is the final regular-season series between the clubs, meaning that the Phillies will need a sweep in order to lay claim to that tiebreaker.

Will it even end up mattering? The season's final month will answer that question. It is something to keep in mind, however -- especially if the Braves find a way to win the series and reduce the Phillies' division lead into a more manageable bite.

3. No Sale, but Schwellenbach is on rise

This series will feature some of the best starters in baseball: Zack Wheeler, Aaron Nola, and Max Fried included. The only big name missing from the bunch is Chris Sale , who instead started on Wednesday. If it's any consolation, Sunday's series finale will include a start from Spencer Schwellenbach, a promising Atlanta rookie on the rise.

Schwellenbach, 24, departed his sixth start this season with a 5.68 ERA in tow. Since then, he's been downright dominant. In his nine most recent outings, he's compiled a 2.60 ERA and 61 more strikeouts than walks in 55 innings pitched.

Sunday's game will serve as Schwellenbach's third time encountering the Phillies. He's recorded a quality start in each of his first two efforts.