By Bruce Levine–

CHICAGO (CBS) — The matchup of the season for the NL Central crown is upon us.

The Cubs and Brewers open a four-game series in Milwaukee on Thursday evening, with Chicago holding a 3.5-game lead — and four in the all-important loss column. A quality pitching matchup awaits in the opener, as Cubs right-hander Jake Arrieta (14-9, 3.48 ERA) faces Brewers right-hander Zach Davies (17-9, 3.89).

Arrieta’s return to form will be crucial for the Cubs, as he hasn’t pitched since Sept. 4 because of a strained hamstring. Arrieta is 2-0 with a 2.08 ERA in two starts against Milwaukee this season. The Brewers lead 8-7 in the season series against the Cubs but are 2-4 in games played at Miller Park.

The Cubs’ division lead has been earned with a strong second half in which they’ve gone 41-22, the second-best record in baseball behind the Indians, who recently had a 22-game winning streak. Chicago trailed Milwaukee by 5.5 games at the All-Star break. Manager Joe Maddon has sensed a different vibe from his players lately.

“The offense has picked up a bit to help our staff out,” Maddon said. “We have had better at-bats, and the guys are finding ways to win. The guys seem totally engaged. That is all important, but we know that pitching drives the engine.”

Chicago’s map to the playoffs continues with four games at St. Louis after this four-game series at Milwaukee. The Cubs’ magic number to clinch the NL Central is eight, and they just need to play decent baseball down the stretch to win the NL Central. In other words, the Cubs need to avoid being dominated by the Brewers and the Cardinals. It was just a couple weekends ago that Milwaukee swept Chicago at Wrigley Field.

The Cubs responded to that poor showing by going on a season-high seven-game winning streak before falling to the Rays on Wednesday night.

Since the All-Star break, the Cubs have a plus-100 run differential, a number that’s second to the Indians’ plus-157 mark. The Cubs have played better defense and produced more clutching hitting in between their blowout wins. All along, the starting rotation has been the Cubs’ engine in the second half, going 31-13 with a 3.54 ERA.

Winning low-scoring games separates the playoff hopefuls from the true contenders, and the Cubs have done that well all season, going 23-15 in one-run games. The Brewers have held their own in that regard as well at 22-20 in such games, which is why they haven’t gone away after fading a bit.

Now, the Cubs are looking to finish those Brewers in the division race, much in the same way as they delivered the big blow to the Cardinals with a sweep last weekend.

“You expect the guys to show up emotionally,” Maddon said of his club over the weekend. “They are totally invested right now, more right now than any point or time of the season. That was my concern — the mental part of it. We have caught a second wind. It appears to be true. So we must retain that the rest of the way through the regular season.”

Bruce Levine covers the Cubs and White Sox for 670 The Score and Follow him on Twitter @MLBBruceLevine.

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