It's no secret that postseason baseball often plays out far different than its regular-season counterpart, but that doesn't mean there's nothing to take away from the previous six months of Major League action.

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From the two Wild Card showdowns to the American and National League Division Series matchups (and potential matchups), some of these meetings will be rematches of regular-season thrillers. While those head-to-head games during the season may not be an indication of what's to come in the postseason, they at least provided some memorable moments and keys to watch out for this October.

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With that in mind, here's a breakdown of the two Wild Card Games and all the potential ALDS/NLDS matchups, highlighting the best games and most notable performances from each of those season series.

NL WILD CARD

BREWERS-NATIONALS

Season series: MIL, 4-2

Run differential: MIL, 42-38

Best game: This was an easy one -- Milwaukee's 15-14 victory in 14 innings on Aug. 17 at Nationals Park was not only the highlight of this season series, but it's in the conversation for the overall game of the year across MLB.

It was a back-and-forth contest in which the Brewers led 5-0 early, then reclaimed an 8-5 edge after the Nats had tied it at 5 apiece. Washington then rallied yet again to take an 11-8 lead, only to have Milwaukee score four in the top of the ninth to jump in front, 12-11. The Nats again knotted the game at 12 in the bottom half, which is how it would stay until Christian Yelich homered -- his second of the game -- in the 13th inning. Washington responded once again in the bottom of the 13th, before the Brewers finally took the lead for good on Eric Thames' two-run homer in the 14th.

Notable performer(s): Arguably the most notable performer from the season series will not be playing in Tuesday's winner-take-all showdown. Yelich went 12-for-25 (.480) with three homers against the Nats this season, but the reigning NL Most Valuable Player will be unavailable for the postseason due to his fractured right kneecap.

Yelich's absence is all the more concerning considering Tuesday's opposing starter, Max Scherzer. Yelich is the only Brewers player to have any success against Scherzer, who has a 2.13 ERA in six starts against Milwaukee since joining the Nationals. Yelich is 10-for-29 (.345) with three homers in his career against Scherzer. Meanwhile, the only other Milwaukee players with at least 10 at-bats against the Nats ace are Mike Moustakas (6-for-36, 11 strikeouts), Yasmani Grandal (1-for-16, nine strikeouts), Lorenzo Cain (0-for-15, seven strikeouts) and Ryan Braun (0-for-14, five strikeouts).

What it tells us about October: Given Yelich's status, it's hard to draw many conclusions from the season series. While the Brewers will certainly miss Yelich's bat, especially given his previous success against Scherzer, they've proven they are not going to go quietly, with or without their superstar. Milwaukee went 13-5 down the stretch following Yelich's season-ending injury, all while averaging five runs per game. Whether they can keep that going against Scherzer is anyone's guess.

AL WILD CARD

RAYS-ATHLETICS

Season series: OAK, 4-3

Run differential: TB, 30-26

Best game: One of the wildest games this season for both teams came against one another on June 20 at the Oakland Coliseum. The game began as a pitchers' duel between Oakland starter Frankie Montas and Tampa Bay's Charlie Morton, who is slated to start Wednesday's AL Wild Card Game. Yet despite entering the ninth tied at 1-1, both offenses finally broke out in the final frame.

The Rays worked a pair of walks to start the inning, then followed with back-to-back run-scoring singles to jump in front. They later pushed across another run to take a 4-1 lead. The A's responded with an RBI single from Marcus Semien before Matt Chapman crushed a walk-off three-run homer off Diego Castillo to give Oakland the 5-4 victory.

Notable performer(s): Morton certainly had the Athletics' number this season, allowing only one run over 13 1/3 innings in his two starts against Oakland. Along with that 0.68 ERA, Morton held A's hitters to a .133 (6-for-45) average.

That said, Matt Olson could be the key for Oakland. He put up a .318/.464/.773 batting line with three homers against the Rays overall this season, and he's also had some success against Morton, going 4-for-12 with a homer and two walks in their career head-to-head matchups.

What it tells us about October: It's been more than three months since these teams met, as all seven meetings came within a two-week span from June 10-23. Needless to say, plenty has changed on both sides since that time. Look no further than the fact that the A's went 55-27 from June 24 onwards, the second-best record in the Majors during that span, behind only the Astros. Still, with this being a winner-take-all showdown, the A's will need to find a way to solve Morton, something they could not do in either of their first two attempts this season.

ALDS

TWINS-YANKEES

Season series: NYY, 4-2

Run differential: NYY, 43-38

Best game: These two potent offenses were on full display in one of the best games of the 2019 season -- a 14-12 10-inning victory for the Yankees on July 23 at Target Field. The Twins jumped out to an 8-3 lead, only to watch the Yankees chip away before taking a 10-9 lead with a five-run eighth inning. The Twins scored two in the bottom half to reclaim an 11-10 edge before the Yanks responded with two runs of their own to jump back in front, 12-11. Minnesota again answered in the bottom of the frame, pushing across the game-tying run to force extras. After the Yanks took the lead with two more runs in the top of the 10th, the Twins loaded the bases before Aaron Hicks raced toward the gap in left-center field to rob Max Kepler with a sprawling game-saving catch to preserve the 14-12 victory.

Notable performer(s): Didi Gregorius played only three games against the Twins this season, but he certainly made the most of them. He went 8-for-10 (.800) with five extra-base hits, including a home run, and 10 RBIs against Minnesota. That includes a 5-for-5, seven-RBI performance in that 14-12 thriller.

On the other side, Nelson Cruz went 6-for-23 in the six meetings this season, but five of those six hits left the ballpark. Cruz's five homers against the Yankees were his most against any non-AL Central opponent this season.

What it tells us about October: Aside from expecting plenty of home runs, it's hard to take much from those six regular-season meetings. After all, the first three came in early May, while the last three-game set ended on July 24. Of Minnesota's top two starters, Jose Berrios did not face the Yanks in either of those series, while Jake Odorizzi tossed six scoreless innings on May 4 in the Bronx before allowing nine runs in four innings against New York on July 24.

ATHLETICS-ASTROS

Season series: HOU, 11-8

Run differential: HOU, 103-75

Best game: This season series had a little bit of everything. There were three extra-inning games and a pair of walk-offs, not to mention the clubs exchanging blowouts on back-to-back days in September. After the Astros routed Oakland for a 15-0 victory on Sept. 9, the A's responded with a 21-7 win on Sept. 10. All that aside, the "best" game between the two may have come all the way back on April 7. The teams combined for seven runs in the first, with Houston holding a 5-2 edge. The A's rallied to take an 8-6 lead, only to have the Astros tie it in the eighth before winning, 9-8, on a two-out walk-off walk by José Altuve in the ninth.

Notable performer(s): No surprise here, but Justin Verlander and Gerrit Cole both stifled the A's, as they did so many teams, this season. Verlander put up a 2.00 ERA in his four starts against Oakland, while striking out 41 batters in 27 innings. Cole, meanwhile, had a 2.08 ERA in two outings against the A's, while holding them to a .136 average and racking up 15 strikeouts in 13 frames.

Olson was Oakland's most successful hitter against the Astros in 2019, clubbing six homers and driving in 17 runs in 14 games. That said, he's 0-for-19 with 12 strikeouts in his career against Cole, and just 5-for-21 (.238) with two homers and seven whiffs against Verlander.

What it tells us about October: While the Astros won the overall season series, 11-8, the A's won six of the final eight meetings, including a pair of contests started by Verlander. The other four victories, however, came against Jose Urquidy, Wade Miley, Rogelio Armenteros and Aaron Sanchez. In other words, the A's would need to find a way to break through against the two leading AL Cy Young Award candidates to have a shot in this potential ALDS matchup.

RAYS-ASTROS

Season series: TB, 4-3

Run differential: HOU, 40-27

Best game: The teams' most recent meeting on Aug. 29 was the most back-and-forth of their seven head-to-head contests this season. The Astros scored in seven of the nine innings, but ultimately dropped a 9-8 decision at Minute Maid Park. Tampa Bay led 1-0, 2-1 and 4-3 before Houston took its first lead of the game at 5-4. The clubs would continue to go back and forth until the Rays reclaimed the lead for good with a three-run seventh inning.

Notable performer(s): It may sound familiar, but look no further than Verlander and Cole. While Verlander had his typical success against the Rays (0.73 ERA in two starts), Cole actually struggled a bit with Tampa Bay. The latter allowed eight runs (five earned) in his two outings against the Rays, though he did rack up 24 strikeouts in just 12 2/ innings.

A lot of Tampa Bay's success against Cole stemmed from Ji-Man Choi, who went 3-for-5 with a homer and four RBIs against the Cy Young Award candidate. Likewise, Rays outfielder Tommy Pham is 9-for-18 lifetime against Cole, with three extra-base hits, including a homer.

What it tells us about October: Four of these seven meetings came more than six months ago in each club's season-opening series in March. The other three, however, provided a bit of a glimpse into this series. Houston started Verlander, Cole and Zack Greinke in the three-game set from Aug. 27-29, while Tampa Bay countered with Morton, Ryan Yarbrough and opener Andrew Kittredge. Houston won two of three, but the Rays had mixed results against Cole (four runs and 14 strikeouts in 6 2/3 innings) and got to Greinke (five runs in 5 2/3 innings).

NLDS

CARDINALS-BRAVES

Season series: ATL, 4-2

Run differential: ATL, 29-27

Best game: Each of the first five meetings were decided by at least three runs, including a 14-3 Cardinals victory on May 14 and a 10-2 Atlanta just two days later. The final regular-season meeting seemed to be trending in that direction, as well, until the Braves erased a 3-0 deficit with a three-run ninth inning to force extras. Brian McCann then worked a bases-loaded walk in the 10th to force in what proved to be the game-winning run.

Notable performer(s): Cardinals ace Jack Flaherty, who put up a remarkable 0.91 ERA in the second half, had a 2.25 ERA in two starts against the Braves. He held Atlanta to two runs over six innings on May 14 in a 14-3 Cardinals' victory. Flaherty then tossed six scoreless frames less than two weeks later on May 26, but the Braves rallied against the St. Louis bullpen for a 4-3 victory. The Braves went just 6-for-38 (.158) against Flaherty, without a single extra-base hit.

What it tells us about October: All six meetings came within a two-week span in mid-May. Thus, Flaherty hadn't even truly taken off yet and -- of the Braves' expected starters for Games 1 and 2 -- Dallas Keuchel hadn't even signed with the team yet and Mike Foltynewicz was in the midst of an early-season slump that later saw him sent to the Minors. He's been an entirely different pitcher since returning on Aug. 5. Far more important than those six early-season matchups from more than four months ago will be the health of Freddie Freeman (right elbow) and Ronald Acuna Jr. (left hip/groin), both of whom are on track to play in the NLDS after missing time last week.

BREWERS-DODGERS

Season series: LAD, 4-3

Run differential: Tied, 27-27

Best game: All seven regular-season meetings between the Brewers and Dodgers came within a 10-day window from April 12-21. After splitting the first six contests, the Dodgers jumped out to a 5-0 lead in the April 21 finale at Miller Park. Lorenzo Cain then hit a two-run homer off Clayton Kershaw in the fifth before Eric Thames hit a game-tying three-run shot off Dodgers closer Kenley Jansen in the eighth. The tie would prove to be shortlived, with NL MVP candidate Cody Bellinger clubbing a go-ahead homer off Josh Hader with two outs in the ninth to give the Dodgers a 6-5 victory.

Notable performer(s): Bellinger's game-winning homer in that seventh and final meeting capped off a dominant run against the Brewers for the Dodgers right fielder. He went 11-for-25 with four homers and eight RBIs in seven games against Milwaukee. Bellinger also worked seven walks, giving him a .440/.531/.920 batting line against Brewers pitchers in 2019.

What it tells us about October: Though much has obviously changed since these teams last met more than five months ago, some things have certainly stayed the same. Bellinger's sensational performance against Milwaukee helped set the tone for his MVP-caliber season. Meanwhile, Jansen's blown save in that April 21 contest also proved to be a sign of things to come, as he finished the year with eight blown saves and a 3.71 ERA -- both the worst of his 10-year career. Of course, the Brewers would also be without Yelich (fractured right kneecap) in this potential NLDS matchup, depriving fans of what could have been an incredible MVP showdown between Bellinger and Yelich.

NATIONALS-DODGERS

Season series: LAD, 4-3

Run differential: LAD, 30-27

Best game: Max Scherzer and Walker Buehler engaged in an impressive pitchers' duel on May 11, with each going seven strong innings. Scherzer allowed two runs on a Justin Turner two-run homer over his seven frames, while Buehler held the Nationals scoreless for seven. Washington, however, broke through against the Dodgers' bullpen in the eighth, with Gerardo Parra providing the decisive blow on a go-ahead grand slam off Dylan Floro.

Notable performer(s): Sure, both teams have an NL MVP candidate in Anthony Rendon and Bellinger, but make no mistake about it, this potential series would be about the two pitching staffs. The Dodgers' starting rotation ranked first in the Majors this season with a 3.11 ERA, while the Nationals were second with a 3.53 mark.

The head-to-head meetings were no different, with each team's star-studded starting rotation trio holding the opponent in check. For the Dodgers, Kershaw, Hyun-Jin Ryu and Buehler combined for a 1.91 ERA while striking out 35 over 33 innings against Washington. On the other side, Scherzer, Stephen Strasburg and Patrick Corbin had a collective 1.67 ERA and struck out 31 batters in 27 innings against Los Angeles.

What it tells us about October: Pitching may still reign supreme -- or it may not. While this series would feature the top two starting rotations in Major League Baseball, it would also pit the NL's two highest-scoring offenses against one another. The Dodgers averaged 5.5 runs per game this season, just ahead of the Nationals' mark of 5.4. Perhaps that's why the Nationals were shut out in two of the first six meetings before surging to an 11-4 victory in the final meeting on July 28 -- a game started by Buehler. The Dodgers would hold the initial advantage with Scherzer pitching in Tuesday's Wild Card Game, but this series could come down to whichever starting rotation trio steps up the most.