ATLANTA -- The Cardinals have had their share of ups and downs in a long season, as they’ve seen their offense rise and fall, their rotation come together and their bullpen stay steady through it all.

St. Louis will put it all to the test Thursday in Game 1 of the National League Division Series against the Braves. How did the Cardinals get here? Here are four key components that altered the course of the season and gave St. Louis its first NL Central title since 2015:

Managerial decision: Leading off with Dexter Fowler

The Cardinals struggled at the leadoff spot for most of the season as Matt Carpenter searched for his swing. Too many times, Paul Goldschmidt and Marcell Ozuna were coming to the plate with no one on base. That changed after the All-Star break, when Fowler began to ascend in the order.

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On July 21, he hit in the No. 2 spot. In his next 61 games -- all near the top of the order -- the Cardinals went 38-23. On Aug. 6, he was moved to the leadoff spot and gave it life. The Cardinals went 31-18 in his next 49 games, and Fowler batted .254/.358/.411 as the leadoff hitter, with 35 walks and seven of his career-high 19 home runs.

After a 2018 season rocked by injuries and career-low numbers, Fowler said he felt a sense of familiarity atop the lineup. The leadoff spot is where he had spent his whole career, and it's where the Cardinals had signed him before the 2017 season to play. And there was no coincidence that when Fowler’s production rose, so did the Cardinals’ offense. The decision paid off for both.

Key transaction: Tommy Edman’s callup

Edman was called up at the beginning of June to bolster the bench when Jedd Gyorko (who was later traded to the Dodgers) was dealing with lower back issues. At the time, the Cardinals were excited about his versatility, but they weren’t sure if he was going to -- or could -- fit into the lineup every day.

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Now, St. Louis can’t keep Edman out of the lineup. He took over third base when Carpenter went on the injured list in July and searched for his swing. It was then that Edman became the spark that the Cardinals needed, and he never slowed down.

Not only can he play second and third base, but he can also play the outfield. And Edman can hit at the top of the order -- which he’s been doing since Kolten Wong strained his hamstring -- or round out the bottom. In September, he batted .350/.417/.660 while hitting six of his 11 home runs on the season.

The 24-year-old switch-hitter’s offensive production from both sides of the plate will come in handy against the left-handers on the Braves’ pitching staff this weekend. Against southpaws, Edman is batting .321/.380/.583, compared to a .298/.339/.471 slash line against righties.

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Breakout player: Jack Flaherty

The Cardinals expected Flaherty to emerge as one of their top pitchers this year, but did anyone expect Flaherty’s dominance over the second half? After posting a 4.64 ERA before the All-Star break and an 0.91 ERA after, the 23-year-old won back-to-back National League Pitcher of the Month Awards in August and September and has become one of the best pitchers in baseball. Only Jake Arrieta (0.75 ERA) in 2015 and Greg Maddux (0.87 ERA) in 1994 had lower ERAs in the second half.

Flaherty can’t point to a specific change he made that led to his second-half surge. He didn’t adjust his mechanics, nor did he throw more of one particular pitch. He credits the change to his mindset -- having the confidence to attack hitters and dare them to hit his fastball or chase his slider. Over the past three months, batters haven’t.

Flaherty’s emergence as the Cardinals’ young ace is a big reason why St. Louis is back in the postseason. He’s led the Cardinals' rotation to a 3.37 ERA in the second half, second in the Majors only to the Dodgers at 3.35. He threw seven scoreless innings with 69 pitches Sunday against the Cubs to clinch the division.

Calling Card: Win with the fundamentals

Cardinals manager Mike Shildt wanted to improve two things about his team at the beginning of the season: defense and baserunning.

He and the Cardinals have accomplished both. St. Louis went from committing the most errors in the Majors in 2018 to the fewest with 66 this year. The Cardinals are tied with the White Sox for most double plays converted in the Majors this year at 170, largely in part because of Goldschmidt, their Gold Glove Award-winning first baseman, Wong, their Gold Glove-caliber second baseman, and All-Star shortstop Paul DeJong.

With 116 stolen bases this year, St. Louis tied for the NL lead with Washington. Four Cardinals stole 10 or more bases, with Wong leading the charge at 24. Compare that to last year, when the Cardinals had just 63 stolen bases (tied for 25th with the Yankees) and two with 10 or more. They improved their stolen base percentage from 66 percent in 2018 to 80 percent in '19.

Sure, it takes more than good defense and baserunning to win games, especially in the postseason against quality pitching and lineups. But opposing teams can’t count on the Cardinals to make many mistakes or give anything away. When the offense has lagged, or the rotation has stumbled, the Cardinals stayed in the race with steady fundamentals.