Nine Homers in August, Five Wins in September: Inside the Cubs' Power Hangover

On the final night of August, the Cubs did something no team in franchise history had ever done. They hit nine home runs in a 17-3 demolition of the Brewers at Wrigley Field — Alex Bregman supplying three of them — and closed the month with 62 homers, the second-highest single-month total in MLB history and an National League record. It was the loudest possible statement from a team chasing a division title.

Two weeks later, that statement is starting to read like a punchline.

The September slide is real

Since September 1, Chicago is 5-7 and has been outscored 60-57. The bats that looked historic on August 31 have gone quiet: over the last ten games the Cubs are hitting .232 with a .747 OPS and a .390 slugging percentage, a long way from the .466 SLG they carried across the previous 20. Five-game win rate sits at .400.

The ugliest stretch came in Milwaukee. The Brewers swept the September 7-9 series at American Family Field by scores of 4-3, 4-3 and 8-6 — three games decided by a total of four runs. For the season, Milwaukee now leads the head-to-head 6-4 across ten meetings, and the NL Central gap is stark: Brewers 93-57 (.620), Cubs 83-67 (.553).

The underlying numbers aren't as bad as the record

Here's the tension. Chicago's season-long offensive profile is better than Milwaukee's — a .768 OPS and .430 slugging against the Brewers' .746 and .406. The Cubs have scored 799 runs, more than Milwaukee's 778, and own a +138 run differential.

The problem is the other side of the ball. The Cubs' team ERA is 4.13; Milwaukee ranks second in MLB at 3.49. Chicago's bullpen has a 4.50 ERA, a 1.426 WHIP, and 12 blown saves against just 13 saves — a coin-flip cluster that turns tight games into losses, exactly the kind that decided that Brewers series.

Recent form reflects it. Over the last five games, the Cubs' ERA is 4.37 with a 1.418 WHIP, and the 15-game ERA sits at 5.16. That's not a rotation you want in a one-run game in October.

Help is coming — and so is a decision

Two things could shift the math. First, Dansby Swanson has been sidelined since August 17 with an oblique strain, and reports point to a return next weekend against Cincinnati. Getting a veteran shortstop back for the final push matters, particularly defensively.

Second, Bregman is in the middle of a genuine tear: .317/.383/.654 over his last 30 days with nine homers and 23 RBI — an .971 OPS that's carrying the lineup while others cool. Pete Crow-Armstrong has been a force all year (41 homers, 36 steals, .933 OPS) and has 14 homers in the last 30 days, though his recent .268 average and 22.2% strikeout rate show he's human.

The concerning part is depth. Justin Steele, Cade Horton, Hunter Harvey, Porter Hodge, Phil Maton, Shelby Miller and Ben Brown all sit on the 60-day injured list. That's a lot of pitching a contender would normally be leaning on right now.

What it means for the stretch run

The Cubs host Atlanta on Monday night at Wrigley, priced around -134 with a 9.5 total — the market still treating Chicago as the stronger side despite the wobble. Reynaldo López goes for the Braves against David Peterson.

Chicago's October case rests on a simple question: can a lineup this dangerous out-slug a pitching staff that ranks middle-of-the-pack in a short series? The August power surge says maybe. The September record — and that bullpen — says not without help. Swanson's return is step one. The rotation holding up is step two. Neither is guaranteed, which is why the final two weeks feel less like a victory lap and more like a stress test.