Felix Hernandez will start the Mariners’ final game of the season, giving Seattle its best chance to return to the playoffs. (Jeff Gross/Getty Images)

Here we are, six months after the season began, ready for 15 Game 162s across both leagues. Much has been decided, but the rest will be sorted out Sunday. And maybe Monday. If necessary.

Here’s what we know, and what we still need to find out.

NATIONAL LEAGUE

What’s been determined:

  1. Washington Nationals (95-66) – NL East champs earn the top seed and home-field advantage through the NLCS and will host the NL wild-card winner in Game 1 of an NLDS on Friday.
  2. Los Angeles Dodgers (93-68) – NL West champs will have home-field advantage in the NLDS and will host the NL Central champ in Game 1 of an NLDS on Friday.
  3. San Francisco Giants (87-74) – Six games back of the Dodgers, they will play the wild-card game on the road.

What’s up in the air:

The NL Central title. If St. Louis (89-72) beats Arizona Sunday OR Pittsburgh loses to Cincinnati, the Cardinals win the division crown and the Pirates will take one of the wild-card spots for the second straight year. If Pittsburgh wins AND St. Louis loses, the teams will play a tie-breaker game on Monday to determine the division winner and the wild-card team.

The Cardinals would host the game because they won the season series against the Pirates, 11-8. The team that doesn’t win the division has some consolation: It will host Wednesday’s NL wild-card game Wednesday against the San Francisco Giants. The division winner will play at the Dodgers in Game 1 of an NLDS on Friday.

The Cardinals will have ace Adam Wainwright (20-9, 2.38 ERA) on the mound against the Diamondbacks, who have baseball’s worst record. The Pirates send out their own ace – Gerrit Cole (11-5, 3.78 ERA) – against another of the best pitchers in the league, Johnny Cueto of the Reds (19-9, 2.29 ERA).

AMERICAN LEAGUE

What’s been determined:

  1. The Los Angeles Angels of Anaheim (98-63) – AL West champs have clinched the best record in the league and home-field advantage through the World Series (by virtue of the American League’s victory in the All-Star Game). They will host the wild-card winner in Game 1 of an ALDS on Thursday.
  2. Baltimore Orioles (95-66) – The AL East winners have earned the second seed and will host the AL Central champion in Game 1 of an ALDS on Thursday.

What’s up in the air:

1. The AL Central title. If Detroit (89-72) beats Minnesota OR Kansas City (88-73) loses to the Chicago White Sox, the Tigers win the division championship and will play at Baltimore Thursday, while the Royals take one of the two wild-card berths and make their first postseason appearance since 1985.

If Kansas City wins AND Detroit loses, a tiebreaker game will be played Monday to determine which team wins the division and which goes to the wild-card game. The Tigers would host the tiebreaker game because they went 13-6 against the Royals this year.

The Tigers are sending marquee trade-deadline acquisition David Price (14-12, 3.36 ERA) up against the Twins, while the Royals will pitch Yordano Ventura (14-10, 3.07 ERA) against the White Sox. Last-place Minnesota has beaten Detroit the past two days, while the White Sox took Saturday’s game against the Royals.

2. The AL wild card: If Oakland (87-74) beats worst-in-the-league Texas OR Seattle (86-75) loses to the Angels, Oakland earns one of the AL wild-card spots. If Seattle wins AND Oakland loses, a tiebreaker game between the Mariners and Athletics would be necessary Monday. The Mariners would host that game because they won the season series – barely – 10-9 over the A’s.

The Mariners may have the advantage in that they will throw ace Felix Hernandez (14-6, 2.34 ERA) against the Angels, whose postseason fate is already determined. The Angels counter with Cory Rasmus (3-1, 2.38 ERA in five starts). The reeling A’s, though, will throw Sonny Gray (13-10, 3.21 ERA) against the Rangers. Gray has a 2.60 ERA in five career starts against Texas.

The loser of the AL Central race will host the AL wild-card game on Tuesday because, whether it’s Detroit or Kansas City, that team will have a better record than Oakland or Seattle.

So strap in. Here we go.