From seemingly the first pitch of the season, the Cubs have distanced themselves from the pack and established themselves as perhaps the most complete team in the Majors.

Long the lovable losers of baseball, the Cubs owned an 11-game lead at the end of June over the Cardinals -- a team that won 100 games last year. When the morning of July 25 rolled around, Chicago had lost just one game in which it had held the lead after the eighth inning.

But when a franchise has gone well over a century without claiming the title, no amount of security is enough. The Cubs proved so on that day, July 25, when they announced they had traded away four players -- including hot prospect Gleyber Torres -- to acquire the most electric closer in the game: Aroldis Chapman .

"If not now, when?" Theo Epstein, the Cubs' president of baseball operations, told reporters about his decision to give up so much for Chapman. "This was the appropriate move, given where we are and what we are trying to accomplish."

Since that day, the Cubs have accomplished a great deal on their way toward clinching their second straight postseason berth. They went an MLB-best 22-6 in August, and have posted a 29-10 record overall since fortifying the bullpen's back end with the hardest thrower in the game.

This past week, the Cubs put even more distance between themselves and the competition, taking six of seven games against potential playoff foes in the Pirates and the Giants. More impressive? Five of Chicago's six wins came in games decided by just one run, showing that the team's bullpen should be a strength come October.

:: Bullpen of the Week winners ::

With games on the line, Chicago's relievers refused to yield, earning them recognition as the Bullpen of the Week presented by The Hartford.

As part of the MLB Prevailing Moments program, each Monday throughout the 2016 season, MLB.com is honoring the "Bullpen of the Week presented by The Hartford." An industry-wide panel of MLB experts, including legendary stats guru Bill James, constructed a metric based on James' widely renowned game-score formula, to provide a weekly measurement of team-bullpen performance.

Here's how the Bullpen Rating System is compiled for each week. For reference, a weekly score of 100 is considered outstanding:

• Add 1.5 points for each out recorded

• Add 1.5 points for each strikeout

• Add 5 points for a save

• Subtract 2 points for each hit allowed

• Subtract 4 points for each earned run allowed

• Subtract 2 points for each unearned run allowed

• Subtract 1 point for each walk

• Subtract 5 points for a blown save

The Cubs' relief corps claimed its second Bullpen of the Week Award this season by limiting opponents to five earned runs on 18 hits over a high workload of 27 2/3 innings, giving them a total of 123 points. Chicago's relievers struck out 33 batters while walking 10 and earned three saves during the week. Two of the Cubs' victories came in games in which their bullpen tossed at least five scoreless innings.

Chicago's bullpen displayed its ability to "step up" by withstanding adversity and succeeding despite unexpected circumstances. Here's a look at their biggest obstacle:

The unexpected: Cubs manager Joe Maddon wasn't quite sure what he was going to get from spot starter Mike Montgomery , who was taking the hill in place of John Lackey to open a big series against the Giants on Thursday. Montgomery, who was acquired from Seattle in mid-July, had performed ably in his first two spot starts. Thursday was a different story, however, as he gave up four runs in a wild four innings that included three walks, a hit-by-pitch, two wild pitches and a long home run by San Francisco's Hunter Pence .

Montgomery exited the game after the fourth inning, trailing 4-3. With Chapman unavailable after pitching in each of the previous three days and setup men Héctor Rondón and Pedro Strop on the disabled list, Maddon suddenly faced quite a tough task to fill the remaining five innings.

How they prevailed: Rob Zastryzny took the ball for first and tossed two perfect innings without allowing a ball to leave the infield. The rookie has now allowed just one earned run in his first 10 1/3 innings in the big leagues.

"Rob Z. again, he straightened the whole game out," Maddon said after the game. "He was very, very good."

Following Zastryzny was another trade acquisition, Joe Smith , who had allowed a .375 batting average to opponents in his first six outings for Chicago. But he breezed through two innings, striking out three Giants and forcing three others to ground out, while the Cubs took the lead on offense.

"He was really, from the side, very sharp," Maddon said. "They had bad swings at him, I thought. Ball was on the ground." With a slim 5-4 advantage, Chicago still had to get three more outs in the ninth -- the inning Chapman usually dominates. But with his closer ruled out, Maddon took a chance on 24-year-old rookie Carl Edwards Jr. to get the job done. Edwards responded, striking out Pence and getting two ground balls to record his first career save.

Five innings earlier, Maddon wasn't sure who was going to give him outs. When the final pitch had been thrown, the Cubs bullpen had recorded 15 consecutive outs.

"From the sidelines, I just loved his focus," Maddon said of Edwards. "Head down, see target, throw baseball. I thought he was great. And his command of his curveball set everything up."

The Braves finished second in the BRS standings this past week with 104 points after allowing only four earned runs over 20 innings. Since returning from the disabled list June 3, Atlanta closer Jim Johnson has converted 15 of 17 save opportunities while recording a sterling 1.38 ERA.