As the season winds down, the margin for error gets smaller. Those in line for the playoffs are one day closer to accomplishing their goal and those slightly behind know time is running out.
There's still some time for things to shake up, but the playoff picture became just a bit clearer on Wednesday. Here's a look at some key developments:
Astros extend lead
The American League West is still airtight, but the Astros -- thanks to some help from the Mariners -- got a little bit of breathing room on Wednesday night.
The Astros' 11-5 victory over the A's, coupled with the Rangers' 6-0 loss to the Mariners, helped Houston increase its lead in the division to two games.
The Astros, as they have so often this season, used the long ball to defeat the A's. Houston tied for the Major League lead with 192 homers after hitting four of them Wednesday night.
Colby Rasmus got the scoring started with a solo homer in the second and Evan Gattis broke the game open with a two-run blast in the fifth.
Video: HOU@OAK: Rasmus crushes homer 444 feet in Oakland
The A's had a four-run fifth of their own, but the Astros' Carlos Gomez and Marwin Gonzalez later hit solo homers to provide some insurance.
The Astros have the edge in the AL West at the moment, but there's still time for that to change. Houston is just 4-8 against the Rangers this season, which is significant because the Texas rivals still have seven games against each other -- starting with a four-game set next week in Arlington.
Video: HOU@OAK: Astros hit four homers, rejoice with gummies
Mets stay hot in D.C.
For the third straight day, the Mets dealt the Nationals a crushing blow. Not only did the Mets sweep the Nationals, extending their NL East lead to seven games in the process, but the Mets did so in Washington, with a trio of late come-from-behind victories.
"We're legitimate. This is not a fluke," Mets manager Terry Collins said.
The Nationals looked like they were going to salvage of third game of the series Wednesday as Stephen Strasburg dominated his way through seven innings, but in the eighth everything changed.
Pinch-hitter Kelly Johnson tied the game with a solo home run and a Yoenis Cespedes delivered the dagger later in the frame with a two-run blast as the Mets won, 5-3.
Video: #THIS: Mets rally in two games to complete sweep
Cespedes has been a tremendous asset to the Mets, hitting .312 with 14 homers and 36 RBIs in 36 games since he was acquired at the Trade Deadline.
"It's like he's some throwback player, like your dad used to tell you about Clemente or Mantle," Johnson said.
Missed opportunity for Yankees
The Yankees had a chance to gain some crowd in the tight AL East race, but were unable to do so.
The Blue Jays, who lead the division by 1 1/2 games, fell, 10-4, to the Red Sox, but the Yankees didn't take advantage and lost, 5-3, to the Orioles.
New York had a chance to close the deficit to just a half game, but couldn't hold on to an early 3-1 lead. The Yankees took that lead into the fifth, but the Orioles tied the game on a Stephen Drew error.
Video: BAL@NYY: Alvarez, Reimold score on Drew's error
"For me, defense has always been there," the second baseman said. "For tonight, it's just one of those things that's tough to swallow. It's frustrating. I'm not going to say it's not, for me especially. Today's over with. It's something that I should have had."
With new life, the Orioles took advantage of the opportunity. Steve Pearce hit a solo homer to left-center field in the eighth and the Orioles tacked on another run in the ninth to secure the win.
However, the Yankees will get another shot to close the gap with Toronto this weekend as the Jays visit the Bronx for a four-game set beginning Thursday.
Twins win in extras
Perhaps the Twins made it harder than it needed to be, but ultimately Miguel Sano's pinch-hit 12th inning homer gave them a win they needed.
"I was so happy," Sano said. "That was a big moment to hit a home run like that."
Video: MIN@KC: Sano crushes homer 447 feet in Kansas City
The Twins topped the Royals, 3-2, in 12 innings and now trail the Rangers by just 1 1/2 games for the second AL Wild Card spot.
After being no-hit through five, the Twins scored two runs in the sixth -- courtesy of Joe Mauer and Kurt Suzuki -- and held a 2-1 lead until Lorenzo Cain tied it up with a sacrifice fly in the eighth.
After the Rangers lost and the Twins blew a late lead it looked like the night could have been a wasted opportunity, but Sano came through with the clutch homer and the Twins will head to Chicago very much in the thick of the Wild Card race.
• After losing the first two games of the series, the Cardinals bounced back and beat the Cubs, 4-3. However, the Cardinals were unable to increase their NL Central lead, which stands at five games, as the Pirates won for the second day in a row.
Video: CHC@STL: Piscotty doubles home two for lead in 8th
• The Angels took advantage of losses by both the Yankees and Rangers as they gained a game in the Wild Card standings after their 3-2 win over the Dodgers. The Angels are 3 1/2 games out of the second AL Wild Card spot, but the Twins stand between the Angels and that spot, as well.
Video: LAD@LAA: Pujols drives in Calhoun to give Angels lead
If the postseason began today ...
Wild Card: Rangers at Yankees
Division Series: Wild Card at Royals, Astros at Blue Jays
Wild Card: Cubs at Pirates
Division Series: Wild Card at Cardinals, Mets at Dodgers
2015 POSTSEASON SCHEDULE
AL Wild Card Game: Oct. 6
NL Wild Card Game: Oct. 7
AL Division Series begin: Oct. 8
NL Division Series begin: Oct. 9
NL Championship Series begins: Oct. 16
AL Championship Series begins: Oct. 17
World Series begins: Oct. 27
William Boor is a reporter for MLB.com. Follow him on Twitter at @wboor.