Welcome to Cubs Playoff Watch, your daily look at the Chicago Cubs as they continue to push toward their first division title since the 2008 season.

Cubs’ Magic Number: 30

The St. Louis Cardinals were off on Thursday, but that didn’t stop the Cubs from gaining ground as they beat the Milwaukee Brewers 9-6 to finish off a series sweep and extend their National League Central division lead to 13 games.

The Cubs are now 18-3 in their last 21 games, their best 21-game stretch since the 1945 season, which coincidentally is the last time they made it to the World Series.

Magic Number to Clinch Home-Field: 34

The Cubs also trimmed their magic number to clinch home-field throughout the National League playoffs with their victory Thursday, but unfortunately they didn’t get any further help as the Washington Nationals beat the Atlanta Braves 8-2.

The results leave the Cubs six games ahead of the Nationals in the race for home-field advantage, but Chicago shouldn’t expect much help in the coming days. The Nationals have three more games this weekend against the Braves, who have the worst record in Major League Baseball.

What’s Next:

After a lengthy stretch that saw them leave the Midwest just once in a month span, the Cubs are heading west for a three-city road trip, and that will get started on Friday night when they battle Nolan Arenado and the Colorado Rockies at Coors Field.

The Cubs will be looking for a measure of revenge against the Rockies when the series begins, as Colorado took two of three from the Cubs in a mid-April series at Wrigley Field. The Cubs scored just seven runs in those three games, with six of them coming in their lone victory against the Rockies.

After a day off Thursday, the Cardinals will return to action as they hit the road against the Philadelphia Phillies. The Phillies were one of the surprise teams in baseball earlier this season thanks to their pitching rotation, but recent woes have knocked them off the pace and have sent them plummeting down the National League East standings, so the Cardinals could be in for an offensive explosion against Philadelphia.

Lurking just a game behind the Cardinals, the Pittsburgh Pirates will be in for a tough test over the weekend as they welcome the Miami Marlins to PNC Park. The Marlins are fighting with the Pirates and Cardinals for the second wild card spot in the National League, and they should provide a real test of Pittsburgh’s playoff hopes.