1. Deep rotation
Of course, this unit is led by ace Adam Wainwright, but he's hardly the only formidable pitcher the Cardinals will be starting in October. Lance Lynn has been pitching like a co-ace, while Shelby Miller is reaping the benefits of throwing more changeups and introducing a sinker to his repertoire. John Lackey was acquired because of his postseason pedigree, and Michael Wacha, if healthy and right ... well, everyone saw what he brought in the playoffs last year.
The Cardinals had some September questions surrounding Lackey and Wacha, though Lackey pitched well his last two times out and Wacha finished his final start with three superb innings. The rotation ranks in the NL's top third in season ERA (3.44), but has had a remarkable run in September. Since the start of the month, the starters have combined for a 2.49 ERA (second best in the NL) and allowed one or no earned runs in 15 of 26 games.
2. The experience/intangible factor
Put simply, the Cardinals have been here before. Yes, every one of the NL's five teams to secure a playoff berth has been a postseason participant within the last two seasons, but none has the wealth of experience this Cards club can tout. The Redbirds are the league's only team to have advanced to the playoffs in four straight years, and, during that span, St. Louis played 48 games under the October spotlight.
The magnified stage won't faze this team because so many of its players have shined on it before. This is a team, too, that has shown an ability to play well in September and carry that momentum over. The Cardinals entered this month with the best September winning percentage (.651) over the last three seasons. This one has been no different, as the Cards won 17 of the 26 games this month to solidify a playoff spot.
3. Shutdown late-inning relief
Yes, Trevor Rosenthal has made the ninth inning much more compelling than the Cardinals would prefer, but many more times than not, he has gotten the job done. The Cards' propensity for playing tight games has led to an abundant amount of save opportunities, which is how Rosenthal finished only behind Atlanta's Craig Kimbrel on the NL saves leaderboard. The good news for the Redbirds, though, is that they have several other arms able to bridge the game to Rosenthal or bail him out if a change needs to be made in the ninth.
Pat Neshek (0.79 WHIP, 1.87 ERA) has been one of the game's best relievers following a winter in which no club offered him a Major League contract. He's been a dominant eighth-inning pitcher for St. Louis. Carlos Martinez has enjoyed a recent resurgence that, not coincidentally, began with Yadier Molina's return behind the plate. Martinez is more than capable of being lights-out toward the end of a game. Insert "ground-ball guy" Seth Maness into that mix, and the Cardinals have a formidable back end of the bullpen.
4. Stingy defense
What was an area of deficiency last season has become a pillar of strength for the Cardinals, who finished second in the Majors in Defensive Runs Saved with 58. The Cards have a plus-DRS at six of their nine positions. This coming a year after St. Louis ranked second to last in the NL with minus-39 DRS. The most noticeable upgrades have come across the infield, and center fielder Jon Jay has rebounded significantly after a subpar defensive year. The Cardinals also stepped up their aggressiveness with shifting, gradually employing more unorthodox defensive alignments each season under manager Mike Matheny.
The improvements in the field have been key in a season where the Cards have played so many close games. The club is 32-23 in one-run games and 15-10 in games decided by two runs.
5. Balanced offense
This is all based upon the lens you prefer to use when evaluating the Cardinals' offense. Without question, there have been unexpected scoring deficiencies and a lack of home runs. But the Cards do have a lineup that doesn't hinge around just one or two key contributors, and that means if one goes cold, there should be others able to capably pick up the slack.
The Cardinals have plenty of proven bats, and with the fickleness of a short series, perhaps they all show up at the same time to offer the Cards the deep lineup they believed they had all along.