For as much of a marathon as MLB's six-month schedule truly is, sometimes 162 regular-season games aren't enough to determine the postseason field.

Expansion teams and the Wild Card Era have certainly contributed to the narrow competition that often extends well into the final month, and sometimes the very best teams are housed in the same division. For an array of quirky circumstances through the years, there have been many occasions where a play-in tiebreaker game is necessary to determine the postseason field -- and some of those contests have proven to be among the Majors' most memorable.

There have been 16 occasions where a tiebreaker was needed beyond the regular season, 12 of which were determined in just one game and four in a best-of-three series. Here is a full breakdown of each:

ONE-GAME TIEBREAKERS

Oct. 1, 2018: Rockies at Dodgers
What was at stake: NL West division title
Winner (score): Dodgers (5-2)
Colorado battled through September, going 19-9, as it chased its first divisional crown. After forcing a Game 163 at Dodger Stadium, the Rockies put a young German M¨¢rquez on the hill, while Los Angeles tabbed rookie starter Walker Buehler.

Buehler carried a no-hitter into the sixth inning, while Marquez gave up a two-run homer to Cody Bellinger in the fourth. Los Angeles pulled away with Max Muncy's 35th homer of the year -- a two-run shot to left-center in the fifth. Dodgers closer Kenley Jansen gave up back-to-back homers to Nolan Arenado and Trevor Story in the top of the ninth but still sealed the Dodgers' sixth consecutive NL West title.

Oct. 1, 2018: Brewers at Cubs
What was at stake: NL Central title
Winner (score): Brewers (3-1)
A heavy underdog to the Cubs at the start of the season, the Brewers made up a 1 1/2-game deficit over the final week to force a Game 163 at Wrigley Field. The Brewers put together a game-winning rally in the eighth with RBI singles by Ryan Braun and Lorenzo Cain, MVP frontrunner Christian Yelich went 3-for-4 while falling just shy of the first NL Triple Crown since 1937, and relievers Corey Knebel and Josh Hader combined for three dominant innings to snuff out the Cubs' hopes.

The Cubs became the first team to continue playing after losing a tiebreaker, as they went on to host the NL Wild Card Game, losing to the Rockies.

Sept. 30, 2013: Rays at Rangers
What was at stake: Second AL Wild Card spot
Winner (score): Rays (5-2)
It took only until the second campaign under the new, two-Wild Card format for there to be an extra layer of drama, as the Rays and Rangers each finished the regular season 91-71, thus needing an extra game to determine who would play the Indians in the AL Wild Card Game. By virtue of winning the season series, 4-3, the Rangers were awarded home-field advantage, but that wasn't enough to stop the red-hot Rays, who had won eight of 10 entering the contest. Evan Longoria hit an early two-run homer, and David Price threw a complete-game gem for Tampa Bay, the first in a tiebreaker game since 1999.

The Rays went on to shut out the Indians two nights later, but they fell to the eventual champion Red Sox in the AL Division Series.

Oct. 6, 2009: Tigers at Twins
What was at stake: AL Central title
Winner (score): Twins (6-5, 12 innings)
In most seasons under a 162-game schedule, 86 wins isn't enough to claim a division title. In 2009, the Tigers and Twins both finished with that many victories yet sat tied atop the AL Central at season's end. Detroit squandered a two-game lead with three to play over the final weekend, while Minnesota won four straight to force the play-in game, which was held at the Metrodome by virtue of the Twins' winning 11 of the 18 regular-season matchups between the division rivals.

What ensued was a back-and-forth, 12-inning thriller in front of 54,088 fans. With one out, runners on first and second and the game tied at 5 in the bottom of the 12th, Fernando Rodney surrendered the game-winning hit to Alexi Casilla, sending those in the stands into a frenzy. However, Minnesota would then run into the juggernaut Yankees in the ALDS, resulting in a three-game sweep.

Sept. 30, 2008: Twins at White Sox
What was at stake: AL Central title
Winner (score): White Sox (1-0)
MLB conducted a coin toss before season's end to determine a play-in game's host, which proved necessary as the Twins and White Sox both overcame what on paper appeared to be superior Tigers and Indians teams to tie for the division lead.

The Blackout Game, as it is now referred to due to the sea of black garb that fans wore amid a sellout crowd on the South Side of Chicago, remains the lowest-scoring tiebreaker game in history. Future Hall of Famer Jim Thome, who would be traded the following season, hit his most memorable homer with the White Sox -- a go-ahead shot in the bottom of the seventh that gave Chicago the edge it needed, while lefty John Danks threw eight scoreless innings of two-hit ball on short rest. Alas, Chicago went on to lose the ALDS to the Rays in four games.

Oct. 1, 2007: Padres at Rockies
What was at stake: NL Wild Card
Winner (score): Rockies (9-8, 13 innings)
This was the game that sparked Rocktober, and it's still vividly remembered across the Rocky Mountain region as perhaps the greatest win in franchise history. The Rockies, who just 15 days prior were in fourth place and 6 1/2 games out, went on one of the most incredible runs of recent memory by winning 13 of their next 14 to force a tie with the division-rival Padres. By virtue of a coin flip, the game was held at Coors Field.

San Diego rolled out that year's NL Cy Young Award winner, Jake Peavy, while Colorado countered with Josh Fogg, who would earn in the nickname "Dragon Slayer" for his poise against elite starters. In the 13th inning, Matt Holliday scored from second base on a head-first slide while tagging up on a line drive by Jamey Carroll to right off eventual Hall of Famer Trevor Hoffman, though the ruling was heavily questioned due to where Holliday's hand crossed the plate. Then-Padres manager Bud Black, now skipper for the Rockies, still claims that Holliday wasn't safe.

Colorado continued its torrid run, going undefeated en route to the franchise's first NL pennant, extending its run to 22 wins in 23 games -- though the Rockies were swept by the Red Sox in the World Series.

Oct. 4, 1999: Mets at Reds
What was at stake: NL Wild Card
Winner (score): Mets (5-0)
In a wildly competitive NL in 1999, 96 wins weren't enough to secure the Wild Card spot for the Mets or Reds, with New York winding up in a Game 163 via a late-season, seven-game losing streak, coupled with Atlanta winning eight straight to claim the NL East. With elimination on the line, the Mets turned to their workhorse, Al Leiter. The lefty delivered a shutout while allowing just one baserunner to reach scoring position, getting a two-run, first-inning lead on a homer from Edgardo Alfonzo.

The Mets would eventually match up against the Braves in the NLCS, but they couldn't overcome a 3-0 series deficit and lost in six games.

Sept. 28, 1998: Giants at Cubs
What was at stake: NL Wild Card
Winner (score): Cubs (5-3)
The Cubs capped one of the most memorable summers in team history -- headlined by Sammy Sosa's historic home run chase -- by punching their first postseason ticket since 1989. But to do so, they needed an extra game against Barry Bonds and the Giants after both teams lost on walk-offs during the final day of the regular season.

After a ceremonial first pitch from none other than Michael Jordan, Chicago starter Steve Trachsel took a no-hitter into the seventh while striking out six, and Rod Beck, who left the Giants after the previous season to sign with the Cubs, induced a pop fly from Joe Carter that sealed the 5-3 win. Chicago scraped by in part by twice retiring Bonds with the bases loaded, but they couldn't get past the 106-win Braves in the NLDS.

Oct. 2, 1995: Angels at Mariners
What was at stake: AL West title
Winner (score): Mariners (9-1)
In the strike-shortened 1995 season, the Angels appeared to be on the cusp of snapping a lengthy playoff drought. With less than two months left in the season, they held an 11-game lead in the AL West, including a 13-game lead over the Mariners, who were in their 19th season of existence and to that point had never made the playoffs. But Seattle finished hot to force an extra game, and both teams sent out their aces on short rest -- Mark Langston for the Halos and Randy Johnson for Seattle. Pitching was the difference, as the Big Unit delivered a complete game in which he struck out 12.

Seattle went on to defeat the Yankees in a classic ALDS, but it fell to Cleveland in the ALCS. It was nonetheless a remarkable season for the Mariners, and the rival Angels' collapse is still remembered as one of the worst of the Wild Card Era.

Oct. 6, 1980: Astros at Dodgers
What was at stake: NL West title
Winner (score): Astros (7-1)
The Dodgers not only overcame a three-game deficit in the final three days to tie the Astros, but they did so by sweeping Houston that weekend in a three-game set at Dodger Stadium, keeping both clubs in Los Angeles for an extra day by virtue of a coin flip.

But the Astros ran away with the tiebreaker en route to their first postseason berth. Joe Niekro tossed a complete game while giving up just six hits and striking out six to pick up his 20th win, and Art Howe drove in four runs. Dusty Baker mustered the only Dodgers run with a fourth-inning single. Houston nearly reached its first World Series later that October but blew a 2-1 lead in the NLCS against the Phillies.

Oct. 2, 1978: Yankees at Red Sox
What was at stake: AL East title
Winner (score): Yankees (5-4)
This was the closest these storied rivals got to meeting in the playoffs until they faced each other in the 1999 ALCS. New York and Boston finished the final day of the '78 season tied at 99-63, and the Red Sox won a coin toss for home-field advantage.

The Sox got out to an early lead with a home run from Carl Yastrzemski and an RBI knock by Jim Rice, but they fell behind in the seventh when Bucky Dent went deep for a three-run homer. Though Boston plated two runs in the eighth, it couldn't overcome the deficit. The Yankees went on to defeat the Royals in the ALCS, then won the franchise's 22nd championship by beating the Dodgers in the World Series.

Oct. 4, 1948: Indians at Red Sox
What was at stake: AL pennant
Winner (score): Indians (8-3)
The Indians blew a 1 1/2-game lead over the Red Sox and Yankees heading into the regular season's final series, setting up the only AL tiebreaker before divisional play began in 1969. Twenty-game winner Gene Bearden started on one day's rest, and Cleveland's offense rewarded him with plenty of support thanks to homers from AL MVP Award winner Lou Boudreau and Ken Keltner. The Indians scored eight runs on 13 hits, while Bearden went the distance to shut down Ted Williams and the Red Sox. Cleveland went on to beat the Boston Braves in the World Series, which remains the franchise's most recent triumph in the Fall Classic.

Oct. 8, 1908: Cubs at Giants
What was at stake: NL pennant
Winner (score): Cubs (4-2)
The Cubs, Giants and Pirates were neck and neck in the standings all season long, so the stakes were high when New York and Chicago squared off on Sept. 23. Giants manager John McGraw penciled in 19-year-old Fred Merkle -- the league's youngest player -- at first base for his first big league start.

The game was tied 1-1 in the bottom of the ninth when Merkle hit a two-out single to put runners on the corners. Al Bridwell followed with what appeared to be the game-winning hit, but Merkle, seeing Giants fans rush the field, turned back to the dugout without touching second base. Cubs star Johnny Evers alertly called for the ball and touched second, and umpire Hank O'Day ruled that the Giants' run did not count because Merkle did not make an attempt to advance to second (and thus became the third out of the inning).

With fans swarming the Polo Grounds field and darkness looming, O'Day ruled the game a tie. But the Cubs and Giants wound up with identical 98-55 records at season's end, forcing them to play a "makeup game" to resolve what soon came to be known as "Merkle's Boner." A then-record crowd of 40,000 watched Chicago claim its third straight pennant by a score of 4-2, and the Cubs went on to win their last World Series title of the 20th century.

BEST-OF-THREE TIEBREAKERS

Oct. 1-3, 1962: Dodgers vs. Giants
What was at stake: NL pennant
Game 1 Winner (score): Giants (8-0)
Game 2 Winner (score): Dodgers (8-7)
Game 3 Winner (score): Giants (6-4)
A pair of California teams that relocated from New York finished tied at 101-61 in 1962. Willie Mays' Giants took advantage of a late-season stumble by the Dodgers -- in their first season at Dodger Stadium -- to force a tiebreaker series. It marked the fourth tiebreaker in NL history and the fourth to feature the Dodgers, who won a coin toss for home-field advantage. It would be the last tiebreaker to use a three-game series format; the NL adopted the AL's one-game playoff for its next tiebreaker in 1980.

The Giants' Billy Pierce pitched an 8-0 shutout in Game 1, outdueling Sandy Koufax, who wasn't his usual dominant self after missing significant time due to injury in 1962. The Dodgers battled back to take Game 2, snapping a 35-inning scoreless skid, and were in position to win the clincher. But the Giants rallied for four runs to advance to the World Series, where they lost to the Yankees in seven games.

Sept. 28-29, 1959: Braves vs. Dodgers
What was at stake: NL pennant
Game 1 Winner (score): Dodgers (3-2)
Game 2 Winner (score): Dodgers (6-5)
The Dodgers rebounded from a second-to-last-place finish in 1958, their first season in Los Angeles, to push the reigning NL champion Braves -- coming off a World Series defeat against the Yankees -- to a tiebreaker series. They won home-field advantage via a coin toss, meaning Games 2 and 3 would be played at the Los Angeles Memorial Coliseum.

John Roseboro's sixth-inning solo homer made the difference in Game 1 at Milwaukee, before the Dodgers secured their first postseason appearance since relocating from Brooklyn with a dramatic comeback in Game 2. They overcame a three-run deficit in the ninth inning, then won, 6-5, on Carl Furillo's walk-off single in the 12th. Los Angeles would go on to claim the franchise's second title, defeating the White Sox in six games in the Fall Classic.

Oct. 1-3, 1951: Giants vs. Dodgers
What was at stake: NL pennant
Game 1 Winner (score): Giants (3-1)
Game 2 Winner (score): Dodgers (10-0)
Game 3 Winner (score): Giants (5-4)
Baseball history buffs recognize this series right away for Bobby Thomson hitting his "Shot Heard 'Round the World," which handed the Giants the pennant in Game 3. That may be the most famous home run in history -- but it only capped an incredible late-season stretch in which the Giants finished 37-8 to overcome a 13-game deficit.

The Dodgers needed a final-day victory over the Phillies just to set up the tiebreaker, and then the Giants took Game 1 on homers by Thomson and Monte Irvin. Brooklyn stayed alive in Game 2, setting up a highly anticipated winner-take-all contest at the Polo Grounds. The Dodgers held a 4-1 lead heading to the bottom of the ninth, but the Giants answered yet again. Thomson sent upper Manhattan into pandemonium with his walk-off dinger into the left-field seats off Ralph Branca, while Willie Mays famously stood in the on-deck circle.

Oct. 1 and 3, 1946: Cardinals vs. Dodgers
What was at stake: NL pennant
Game 1 Winner (score): Cardinals (4-2)
Game 2 Winner (score): Cardinals (8-4)
St. Louis entered the campaign as the NL's heavy favorite, but the upstart Dodgers built a seven-game lead by July 4 to liven up the race. The Cardinals scratched and clawed their way back to set up a three-game tiebreaker series -- the first of its kind in AL or NL history.

Cards starter Howie Pollet took advantage of early run support to win the opener in St. Louis. Then the Redbirds took care of business in Game 2 at Ebbets Field -- which also doubled as the first televised postseason baseball game -- to clinch the pennant. The Cardinals went on to beat the Red Sox in the World Series, thanks to Enos Slaughter's "mad dash" in Game 7.