On April 21, the St. Louis Cardinals, then with a two-game lead atop the NL Central, took the field against the Washington Nationals in the first of what would be 20 games in 20 days.

Such a stretch is difficult enough as is, but the challenges mounted as the games wore on. Chest and knee injuries knocked All-Star catcher Yadier Molina out of the lineup three times in one four-day stretch and left him at less than 100 percent once he returned. Another All-Star, third baseman Matt Carpenter, also missed four straight games due to a condition the Cards mysteriously called “extreme fatigue.” But the crushing blow came on April 25, when staff ace Adam Wainwright ruptured his Achilles tendon and was lost for the year. Given all of that attrition and no time to rest, the Cardinals could have — even should have — lost ground in the NL Central race.

Instead, St. Louis reeled off 14 wins in those 20 games, including a 6-3 record in the nine games played against 2014 playoff teams. When the dust settled on Sunday, the Cardinals had extended their NL Central lead to 6.5 games, the biggest gap in the majors.

Draft Well and Pitch Low

Despite the loss of Wainwright, the team’s biggest strength remains its pitching: The Cards’ 2.76 ERA leads the majors, and their 3.15 FIP ranks second. Flip through the names populating the pitching staff, and the biggest reason for the Cardinals’ sustained success becomes obvious: They are a scouting and player-development powerhouse.

The top two talents in the current rotation are Lance Lynn and Michael Wacha. Although both were top-40 picks, they each came into the league with more question marks than we’re accustomed to seeing attached to guys with white-collar pedigrees. Yet as we’ve seen this season, Lynn and Wacha have gone on to exceed their post-draft expectations.

The Cards nabbed Lynn with the 39th pick in the 2008 draft. And although a player picked that high often comes with a shiny scouting report, Lynn did not. See if you can keep track of all the backhanded compliments in this MLB.com writeup of the pick:

Lacking great pure stuff, Lynn is a level behind the elite college arms in this Draft class. But he makes the most out of his average offerings with excellent command, a knowledge of how to pitch and a real competitive streak on the mound. He’s done a good job of maintaining his weight this year and will have to continue to do so as a pro. He won’t wow you, but he’s the type who could be a solid innings-eater who presumably won’t take long to be big-league ready.

Now 28, Lynn has become much more than an innings-eater, and he actually does wow you. Since Opening Day 2013, only nine National League pitchers have fared better by FIP, and only seven have tossed more innings. After tossing six shutout innings Tuesday, Lynn’s ERA dropped to 3.27, belying even better underlying numbers: a top-10 strikeout rate (51 in 41.1 innings) and a continued stinginess with the long ball — just two homers allowed in seven starts, an impressive but also typical stat for a Cardinals pitcher. Lynn can’t quite hang in the Kershaw-Wainwright phylum of superstars, but he’s just half a notch below that, ranking 10th among all pitchers in WAR.

Four years after Lynn, Wacha was the 19th pick in the 2012 draft, a relatively favorable spot for a team that had just won the World Series. Although Wacha certainly got attention as a 6-foot-6 right-hander coming out of Texas A&M, again, truckloads of skepticism colored his MLB.com draft report:

Wacha jumped on the prospect map very early into his Aggies career and while he’s still the top college arm in Texas, he’s not quite as high profile now as people thought he might be after the start of his college career. Wacha reminds some of Jon Garland because of his size. He has a live, quick arm that can produce a fastball up to 94 mph, sitting comfortably in the 92-93 mph range. There might be more there, pointing to a future plus fastball. He can spin a curve, though some think he’d be better off throwing a slider at the next level. He doesn’t throw a changeup much, but it could be an average offering. He can throw his pitches for strikes and goes right after hitters.Even if he’s not the elite college arm some thought he would be, he still has the chance to be a big, durable big league starter. And those don’t grow on trees.

Garland was a 6-foot-6 righty himself who spent 13 years in the big leagues, won 136 games, and racked up 22 Wins Above Replacement; those last two credentials are rarer than you’d think for a position rife with injury and attrition risk. Still, that comparison felt like a subtle dig, as did the implication that Wacha’s changeup “could be an average offering.” In fact, Wacha’s change has been a great weapon from day one, as it suppresses batting average and generates plenty of swings and misses. Like other Cardinals pitchers, he has benefited from the team’s coaching and advance-scouting prowess, enabling him to outfox opponents in big spots like the first two rounds of the 2013 playoffs. This year, Wacha’s 5-0 record and 2.09 ERA don’t match up with his much lower strikeout rate. But the 23-year-old righty has offset that drop in whiffs with a career-best 54.8 percent ground ball rate, which highlights a Dave Duncan lesson that’s carried forward to a new generation of Cards pitchers: Keep the ball down in the zone, and good things will happen.

Flip through the pitching staff and you’ll see plenty more examples of scouting, drafting, and player-development success for pitchers far less heralded than Lynn and Wacha. With a 41st-round pick, the Cards snagged Kevin Siegrist, a lefty reliever who struggled last year but was one of the best in the game in 2013 and again so far this season. Seth Maness (11th round) and Mitch Harris (13th round) are both big league bullpen members in good standing. Ninth-rounder Tyler Lyons holds down the fifth spot in the rotation for now, and 22nd-rounder Jaime Garcia could vie for a rotation spot of his own if he can come back healthy later this month as hoped. Twenty-first-round pick Trevor Rosenthal wasn’t even a pitcher when he was drafted, and Carlos Martinez was an amateur free-agent signing, but both have been molded into successful major leaguers. Thirty-six-year-old John Lackey came over in a trade with the Red Sox in 2014, but the highly effective veteran might not have landed in St. Louis if the Cards hadn’t had third-round pick Joe Kelly and eighth-round pick Allen Craig to dangle.

Once they’ve identified the undervalued pitching talent, the Cards coach it up. St. Louis ranks 10th in MLB with a 46.2 percent ground ball rate thanks to a teamwide commitment to keeping the ball down. It’s resulted in tons of soft contact, with St. Louis ranking sixth in the majors in that stat. And combined with a spacious home park, that approach has made the Cards the second-least homer-prone team in baseball.

It would be easy to chalk up all of this early success to just two things: having an eye for talent and jumping up and down until everyone throws knee-high strikes. But of course, baseball is rarely that simple — especially when #CardinalsDevilMagic is involved.

Better to Be Lucky and Good

When hitters have stepped to the plate in big spots against the Cardinals this year, they’ve hit like Bartolo Colon in a straitjacket. With runners in scoring position, St. Louis opponents have batted just .189, the lowest mark in baseball by a mile. And it’s not just a low batting average either: Cards opponents sport a miserable .268 OBP with RISP and have slugged an anemic .254 in those spots. Things don’t get much better in close-and-late situations, in which opposing teams are batting a league-low .221.

Now, a good bullpen can help partly account for impressive close-and-late numbers, but this year’s mark still falls well below the thresholds for 2013 (.243) and 2014 (.238). As for holding hitters in check with runners in scoring position, a team could theoretically benefit from one or two pitchers being particularly effective from the stretch, and if you want to argue intangibles, maybe a bunch of cool customers could shave a couple points off batting averages here or there. But the gulf between this season’s sub-Mendoza RISP numbers and what we’ve seen the past two seasons (opponents hit .253 with runners in scoring position in 2013, and .242 last year) suggest something well beyond the norm.

In short, they’ve been a little lucky. According to cluster luck, Cardinals pitchers have allowed 16 fewer runs than you’d expect from a team with average hit sequencing results — thanks largely to those microscopic numbers with RISP. And per FanGraphs Base Runs, the Cards have won three more games than you’d expect based on their component stats (hits, walks, strikeouts, home runs, etc.), placing them behind only the surprising Twins and Mets for “most fortunate team” honors.

Add it all up and we see how a team can start the year with the best record in the majors: Be very good — and also very fortunate.

What Next?

Whether or not this pace lasts depends in large part on how the rotation fares without Wainwright going forward. While Lynn and Wacha have led the way, Lackey has also fared well, allowing just eight unintentional walks and two homers in 39.1 innings. Meanwhile, Lyons has made just two major league starts this season, but he showed some encouraging signs in his last start against the Pirates, allowing two earned runs, striking out five, and walking just one over five innings.

Waiting in the wings are Garcia, the veteran lefty who’s thrown only 99 major league innings since Opening Day 2013 but has a solid track record before that, and Marco Gonzales, the 23-year-old rookie left-hander with only 34.2 innings of major league experience but also impressive stuff and a first-round pedigree. There’ve even been whispers about a possible six-man rotation once Garcia or Gonzales is healthy and ready to take on a starter’s workload. The Cardinals could also roll with both of those lefties, and send Martinez back to the bullpen if they’re frustrated with his performance as a starter, which includes a strikeout an inning but also 18 walks and a 4.89 ERA.

That starting pitching depth, combined with other favorable factors, could prompt the Cards to stand pat. Carpenter is back in the lineup after that four-game absence, Matt Holliday and Kolten Wong have been on-base fiends, and the struggling Jason Heyward and Molina should fare better as the year goes on. Plus, the Cardinals’ NL Central competition could continue to disappoint. The Pirates offense could keep struggling while Andrew McCutchen hobbles, and the Cubs could keep up the Jekyll-and-Hyde act in which Anthony Rizzo dominates but several of his lineup mates don’t do enough, while a leaky defense lets down a pitching staff that looks good by peripheral stats but struggles to prevent runs.

Still, there’s a good chance that GM John Mozeliak also explores the trade market, where the list of available starters could soon include everyone from Cole Hamels and Johnny Cueto to lower-tier options like Scott Kazmir, Mike Leake, and Kyle Lohse. This club, which acquired Holliday and many other key contributors at past deadlines, has rarely shied away from making impactful moves when necessary.

Cardinals fans shell-shocked by Wainwright’s Achilles like to point out that St. Louis won the World Series the last time the big right-hander suffered a season-ending injury. But the reasons for optimism go beyond superstition and coincidence. With a balanced roster, a deep, mostly homegrown pitching staff, and the expectation that Mozeliak will wheel and deal this summer if he feels the need, St. Louis has multiple unenchanted avenues toward success — especially when the dark arts have already gotten them this far.