Four weeks ago today, the St. Louis Cardinals were reeling from a 9-0 loss to the distinctly undermanned New York Mets. Having won a dramatic extra-inning game just one night before, the Cardinals were helpless against Jon Niese, Nelson Figueroa, and Bobby Parnell as Kyle Lohse got rocked for five runs in 2 2/3 innings. They maintained a first-place tie with the Chicago Cubs, who were themselves shut out in Cincinnati by Justin Lehr. There was a real sense that this would be the race to watch down the stretch, with the loser likely the favorite for the wild-card slot, the NL Central set to once again send two teams to the postseason.

Today, the Cards have a 10½-game bulge over the Cubs, the largest of any division leader. The question for them isn’t whether the Cardinals will make the playoffs, but whether they, not the Phillies or Dodgers, are the best team in baseball. Since that blowout loss to the Mets, the Cardinals are 20-4, having allowed fewer than three runs per game. They’ve been a little fortunate-their runs scored and allowed would project to 17-7 in that time-but mostly they’ve stopped the other team cold, enabling them to win with a good, not great, offense. On balance, they’ve played a set of below-average offenses in that time, which has helped them keep scoring down, but again, that doesn’t explain 2.9 RA/G.

What does explain it is a pitching staff that doesn’t give anything up. Cards pitchers have walked just 51 men unintentionally in that time, against 165 strikeouts, a better than 3-to-1 ratio-as a staff. They’ve allowed just 15 home runs in 24 games. Back in May, their pitchers went more than 11 games without allowing a long ball; right now they’re working on a 10-game stretch in which they’ve allowed just four. If you don’t walk the opposition or allow them to go deep, you’re two-thirds of the way to keeping them off the board completely. Adam Wainwright and Joel Pineiro have walked just four men apiece in this span, covering five starts each. By pounding the strike zone, these pitchers are able to work deeper into games as well, enabling the Cardinals to have a higher percentage of innings thrown by their better pitchers.

The defense has been supportive as well. Cardinals pitchers have allowed a .284 BABIP during this time, as the addition of Matt Holliday in left field and the decision to play Brendan Ryan at shortstop have paid dividends. Cards’ fielders have allowed just four batters to reach on error in the team’s last 24 games. Yadier Molina‘s tremendous arm has also been a factor: Cardinals opponents have just five stolen bases in eight tries in that span. So now you have a team that isn’t giving up walks, home runs, or stolen bases, and is limiting hits to a bit more than one on every four balls in play. The question starts to become not “how did they allow just 69 runs in 24 games?” but “how did the other guys even get 69?:

Consider now that of those 24 games, three were started by Mitchell Boggs and three by Kyle Lohse. The Cards took three of the four losses in this stretch with one of those two guys making the start. When starting their top three, the Cardinals have lost just one game since August 5, that a 4-3 loss to the Astros last Thursday in a game decided by a solo home run in the ninth inning. Take it back to the Matt Holliday trade, and call John Smoltz the team’s likely fourth starter in a post-season series, and you find that the Cardinals who will be playing in the postseason, the ones with Holliday and without Boggs and Lohse, are 23-2.

Now, the question I was asked earlier today on the radio, about whether the Cardinals rather than the Dodgers or Phillies are the best team in the National League, starts to make sense. The Cardinals are 27-9 with Matt Holliday, and 23-2 with Matt Holliday and one of their post-season starters on the mound. That team has outscored its opponents 133-52. That team looks like the best in the National League, and quite possibly the best team in baseball. If any NL team has a case for that crown right now, it’s the Cardinals’ playoff roster, which has basically been unbeatable for nearly six weeks.

The Cards’ edge in the NL Central wouldn’t be as big as it is without the Cubs’ failures. However, even if the Cubs had played .600 ball since the last time the two teams were tied, they would be 5½ games back, and the Cards would have the third-biggest lead of any team in baseball. That’s how good the Cardinals have been-even projecting sunshine and roses for the Cubs would yield a big lead for St. Louis. In reality, the Cards have the kind of lead that’s going to allow them to spend most of September resting veterans, managing workloads-remember, Chris Carpenter hasn’t done this in three years-and figuring out exactly what the bullpen will look like in a month’s time.

What’s scary is that the Cards may yet get a little better. Third base had been a black hole all season long as a result of Troy Glaus‘ unavailability due to a shoulder injury. Glaus returned in a pinch-hitting role Wednesday, and if he can come anywhere close to his career performance, he’ll be an asset for a team that has struggled to get adequate performance from the many replacements it’s tried, up to and including Mark DeRosa, who has just a .310 OBP as a Cardinal. Glaus didn’t hit well during an extensive rehabilitation period, so he’s not guaranteed to help-and Tony La Russa may not even play him much-but there’s upside here that clearly isn’t present in DeRosa or Joe Thurston.

Regardless of whether Glaus has an impact, the Cardinals have established themselves as the dominant team in the National League through their performance. The current version of the team is a .750 squad, and the team that will be playing in the NLDS is a ridiculous .920 team. As good as the Phillies have been with Cliff Lee, and as much talent as the Dodgers have, neither can measure up to that.