The first postseason spot was claimed Sunday when the Nationals clinched the National League East with a win over the Phillies and when the Braves topped the Marlins. Much of the playoff field still remains in flux, however, with Wild Card and pennant races heating up.

Here's where we stand heading into today:
Home-field advantage
The Indians continued their run as baseball's hottest team, extending their franchise-record winning streak to 18 games with a sweep of the Orioles this weekend. Cleveland (87-56) has moved ahead of the Astros (86-57) as the American League's top team.
The Indians are also just five games behind the Dodgers for the top record in baseball, which would give them home-field advantage throughout the playoffs.
The slumping Dodgers (92-51) have lost 10 straight games, allowing the Nationals to gain ground in the NL. Washington has won 11 of 15 to climb within four games of the Dodgers for home-field advantage.
• Explaining possible postseason tiebreakers
NL Central race
The NL Central race tightened this weekend as the Brewers completed a three-game sweep of the Cubs while the Cardinals won three straight against the Pirates in St. Louis. Two games now separate the Brewers and Cardinals from the first-place Cubs in the standings.
"That was a big thing, coming here into their ballpark and showing we can compete," Brewers starter Zach Davies said of the sweep. "It's going to make [the rest of] September very interesting and fun to play for."
NL Wild Card
The Cardinals and Brewers push up the NL Central standings also has them challenging the Rockies for the second NL Wild Card spot. Both Arizona -- which owns the top spot, five games ahead of the Rockies -- and Colorado won Sunday, maintaining their distance from the NL Central pairing.
"I think there's more energy, just due to the fact that we're getting close," Cardinals outfielder Randal Grichuk said. "The division isn't out of reach, and we know we have a chance to win it. And if not, make a Wild Card. We can feel the playoffs aren't too far away, and it's in our grasp."
• Wild Card standings
American League Wild Card
The AL Wild Card picture remains as crowded as ever with eight teams in the mix for the one-game playoff. Backed by two home runs each from young stars Aaron Judge and Gary Sanchez, the Yankees solidified their place at the top of the group with a win over the Rangers on Sunday. They're 3 1/2 games ahead of Minnesota for the top AL Wild Card spot. The Angels, who beat fellow the Wild Card-hopeful Mariners, are just a game behind the Twins, while the Royals, Rangers, Orioles, Mariners and Rays aren't far behind.
If the postseason began today...
AMERICAN LEAGUE
Wild Card: Twins at Yankees
Division Series: Wild Card at Indians, Red Sox at Astros
NATIONAL LEAGUE
Wild Card: Rockies at D-backs
Division Series: Wild Card at Dodgers, Cubs at Nationals
2017 POSTSEASON SCHEDULE
AL Wild Card Game (1-game playoff): Oct. 3
NL Wild Card Game (1-game playoff): Oct. 4
AL Division Series begins (best-of-5, 2-2-1 format): Oct. 5
NL Division Series begins (best-of-5, 2-2-1 format): Oct. 6
AL Championship Series begins (best-of-7, 2-3-2 format): Oct. 13
NL Championship Series begins (best-of-7, 2-3-2 format): Oct. 14
World Series begins (best-of-7, 2-3-2 format): Oct. 24