Baseball fans, get ready for a wild ride.
The American League West remains up for grabs, along with both AL Wild Card spots and the No. 1 seed in the AL playoffs. The host for the National League Wild Card Game presented by Budweiser will be determined by Sunday's results.
All postseason tiebeaker possibilities explained
In the AL, the Rangers, Astros, Angels, Yankees, Royals and Blue Jays all have something to play for, while in the NL, the Pirates and Cubs still have designs on being the Wild Card hosts.
The last day of the regular-season schedule has arrived, but this year, an important new wrinkle promises to make it as thrilling as ever. For the first time, every game with playoff implications will begin at 3 p.m. ET on Sunday. (The Braves and Cardinals will play a doubleheader starting at 1 p.m. ET to make up Saturday's rainout, but those games will not impact the playoff picture as St. Louis has already clinched home-field advantage through the NLCS.)
Postseason picture: If the playoffs started today
There's also a chance that not every question will be settled on Sunday, with a tiebreaker game on Monday still a possibility.
With that in mind, here is a look at what to watch for on what should be a heart-pounding afternoon of baseball.
Texas showdown -- LAA @ TEX
Baseball can't get much crazier than it did at Globe Life Park on Saturday, when the Rangers held a 10-6 lead before the Angels scored five runs in the top of the ninth for an 11-10 victory. The Halos became the first team since the Cardinals on June 25, 2012, to win a road game it trailed by four in the ninth, according to ESPN.
The comeback prevented the Rangers from clinching the AL West, while the Angels remained one game behind the Astros for the final Wild Card spot.
"Nobody's ready to go home," Angels outfielder Kole Calhoun said. "We're not quitting. We're not quitting on each other. We're going out and playing for each other."
So what will these teams do for an encore? Texas, needing a win or an Astros loss to claim the division, has the luxury of starting Trade Deadline acquisition Cole Hamels. The left-hander is 6-1 with a 3.86 ERA in 11 outings with the club, though he gave up six runs his last time out, against Detroit. In dire need of a win, the Angels are turning to right-hander Garrett Richards, who will start on three days' rest for the first time in his career.
"I trust we'll bounce back," Rangers manager Jeff Banister said. "We have bounced back all year. These guys have found a way to bounce back every time they have been against the wall. I feel confident."
Win and in -- HOU @ ARI
The Astros have a number of postseason scenarios in the air, and they can't be eliminated from contention Sunday. But first thing's first: Houston has already clinched at least a tie for the second AL Wild Card and can clinch a playoff berth with a win at Chase Field in an Interleague matchup against the D-backs.
The AL West crown and both AL Wild Card spots are in play for the Astros.
"We showed up tonight and took care of our business, which is all we could ask for in Game 161," Astros manager A.J. Hinch said after a 6-2 win over the D-backs. "I'm proud of our guys. They did a really good job of staying focused from the beginning. It's a good win for us and certainly puts pressure on a lot of teams around us."
If the Rangers beat the Angels, they win the division, regardless of what Houston does. However, the Astros can force a one-game tiebreaker to decide the division if they beat Arizona and the Rangers lose. The tiebreaker would be played Monday in Arlington, by virtue of the Rangers winning the season series against the Astros, 13-6. The loser of a potential tiebreaker could have home field in the AL Wild Card Game presented by Budweiser, but only if the Yankees also lose on Sunday.
The Astros can clinch the second AL Wild Card outright if they win, or if the Angels lose.
"To be in this position at the end of the year is what you play for, what makes it fun," Astros catcher Jason Castro said. "It's one of the most exciting seasons of my career. I'm happy about [it], but we're not done. We're still hungry and we still have a lot left to prove."
It doesn't end there. The Astros could tie the Angels for the final Wild Card spot if they lose and the Angels win. In that scenario, a one-game tiebreaker would be played Monday in Houston, based on the Astros winning the season series over the Angels, 10-9. The winner of that game would travel to face the Yankees in the Wild Card Game.
The Astros could also host the AL Wild Card Game if they beat the D-backs and the Yankees lose to the Orioles. In this scenario, the Astros and Yankees finish with an identical 87-75 record and the tiebreaker goes to Houston by virtue of winning the season series, 4-3. If The Yankees lose Sunday and the Rangers fall in a potential Game 163 vs. the Astros for the AL West title, the AL Wild Card Game would be played in Arlington, since the Rangers hold the tiebreaker after going 5-2 vs. the Yankees in the season series.
A Yankees win over the Orioles, however, would clinch home-field advantage for the Bronx Bombers in the AL Wild Card Game.
Note: Even though a Monday tiebreaker game counts as a regular-season game for statistical purposes, it does not affect the standings as far as tiebreakers go. So, for example, if the Rangers, Astros and Yankees all finish 87-75, and the Rangers and Astros had to play a tiebreaker game on Monday for the AL West title, the loser of that game would still host the Wild Card Game by virtue of a head-to-head record against the Yankees, even though their record in the standings would be 87-76, seemingly a half-game behind New York.
Ks for Kershaw -- SD @ LAD
The Dodgers have already clinched home-field advantage in the NLDS against the Mets heading into Clayton Kershaw's final tuneup in advance of his expected Game 1 start on Friday at Dodger Stadium.
Kershaw, who has a shot at his fourth NL Cy Young Award in five years, has a personal milestone at stake Sunday. With 294 strikeouts, Kershaw needs six more to become the first big leaguer to reach the 300 mark since Curt Schilling and Randy Johnson in 2002, as well as the second Dodger to do so, after Sandy Koufax (1963, '65-66).
Kershaw might not have much time to collect those K's, however, as manager Don Mattingly has said he will be limited to three or four innings.
Bring it back to Pittsburgh -- CIN @ PIT
PNC Park already has hosted two NL Wild Card Games, and the Pirates could make it three in a row with a win over the Reds or a Cubs loss in Milwaukee.
J.A. Happ wasn't one of the biggest names moved before the Trade Deadline, but the left-hander has come up huge for the Bucs, going 6-2 with a 2.04 ERA in 10 starts. He will take the ball against Reds rookie Josh Smith, who owns a 7.22 ERA over eight big league games (six starts).
The Cubs can still host the NL Wild Card Game if they beat the Brewers and the Pirates lose. Chicago owns the tiebreaker by virtue of winning the season series against Pittsburgh, 11-8.
"For me, it's all about our fans," Chicago manager Joe Maddon said. "To be able to [play at home] is all about the fans, No. 1."
Here's Johnny -- KC @ MIN
The Royals' 5-1 win over the Twins on Saturday eliminated Minnesota from postseason contention and moved Kansas City closer to clinching the AL's best record, which would guarantee it home-field advantage throughout the postseason, including the World Series, by virtue of the AL's 6-3 win in the All-Star Game.
The Royals now are one game ahead of the Blue Jays, who hold the tiebreaker after winning the season series, 4-3. Right-hander Johnny Cueto will take the mound for the AL Central champs at Target Field as he looks to notch his fourth consecutive quality start. Overall, Cueto has a disappointing 4.95 ERA in 12 outings for the Royals.
However, if the Royals lose and the Blue Jays beat the Rays at home, Toronto would secure the top seed in the AL.
"We've got to go out and play to win tomorrow," Royals manager Ned Yost said. "It doesn't matter what Toronto does, we have to win."
Andrew Simon is a reporter for MLB.com. Follow him on Twitter @AndrewSimonMLB. Austin Laymance is a reporter for MLB.com.