With three weeks remaining in the regular season, the most compelling division series race appears to be taking place in the National League Central, where the Cardinals entered Monday with a 4 1/2-game lead over the Cubs by way of a two-week stretch that produced 10 wins and four losses.

Why is this race so interesting? Because although 20 games remain on the Cubs' schedule, they play St. Louis seven more times -- all in their last 10 games of the season.

The two teams meet next at Wrigley Field for a four-game set Sept. 19-22, and they'll end the season at Busch Stadium with three games, Sept. 27-29.

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On days when they're not matched up, Chicago seems to have the "easier" schedule. The Cardinals are the only above-.500 team the Cubs will play down the stretch, while St. Louis plays almost exclusively against teams with winning records, save for its upcoming three-game series with Colorado.

On to the rankings ...

Biggest jump: There was very little shuffling in the rankings this week. The largest margin, in fact, was two, accomplished by the Phillies (No. 15 to 13) and Reds (No. 19 to 17). The Phillies are still hanging in the NL Wild Card race, just two games out of the second spot. The Reds aren't in a postseason race, but their third baseman is doing a good job keeping his team in the conversation. Eugenio Suárez hit two homers Sunday to bring his season total to 44, just one off the pace of MLB leaders Pete Alonso and Mike Trout.

Biggest drop: The Red Sox and Mets dropped two spots -- Boston from No. 12 to 14, and the Mets from No. 14 to 16. Again, not a huge difference from last week, but it's looking like this year's postseason field of 10 will not include last year's World Series champs.

Power Rankings Top 5:

1) Astros (1 last week)

Thanks in part to their 21-1 rout of the Mariners on Sunday, the Astros have a firm hold on the largest run differential in baseball at +240. That's a smidge better than the NL-leading Dodgers (+233) and significantly better than the other AL division leaders (Yankees +169; Twins +168). Meanwhile, Alex Bregman is one of many Astros in the midst of an offensive tear. He has reached base in 31 consecutive games, and his season OPS is up to .995. He could become the first qualified Astro to finish a season with a 1.000 OPS since Lance Berkman in 2006.

2) Yankees (2)

The Yankees have won 10 of their past 13 games, while outscoring the opposition 65-44. On Sunday, they hit three home runs to set a single-season club record with 268 homers, surpassing last season's franchise record of 267, which was, at the time, also a Major League record. The Yankees' win over the Red Sox on Sunday kept them tied with the Astros for the best record in the AL. The Bronx Bombers will have to end the season with one more win than Houston to gain home-field advantage in the AL playoffs, by virtue of the Astros winning the season series, 4-3.

3) Dodgers (3)

The Dodgers' magic number is down to 2 after they shut out the Giants on Sunday. Los Angeles has only been swept in a series of at least three games once this year. Corey Seager knocked a three-run homer, a good sign after logging just three hits in his prior 26 at-bats across seven games. Conversely, Joc Pederson had a good week, recording nine hits in his past 16 at-bats with five homers, two doubles and nine RBIs in his past six games.

4) Braves (5)

The Braves lost Sunday, ending a nine-game winning streak, but that hardly matters in a division race they've all but secured thanks to a blistering three weeks that produced a 15-3 mark. Atlanta has outscored opponents 65-42 over its past 10 games, and despite the loss on Sunday, it's notable the Braves' now-concluded 13-game home winning streak was a Modern Era franchise record. Also -- and this seemed unfathomable even a month ago -- the Braves are still in the mix for home-field advantage in the postseason. In the loss column, they're just three games behind the Dodgers.

5) Twins (4)

Mitch Garver is batting .400 with five homers and seven RBIs in his past seven games, and his 29 homers this year set a Twins record for catchers. The Twins have one more challenging week -- they host the Nationals for three and travel to Cleveland for three -- before they finish the season with 13 games against sub-.500 teams (White Sox, Royals and Tigers).

The rest of the top 20:

6. Nationals (6 last week)

7. A’s (7)

8. Cardinals (9)

9. Rays (8)

10. Cubs (11)

11. Indians (10)

12. D-backs (13)

13. Phillies (15)

14. Red Sox (12)

15. Brewers (16)
16. Mets (14)

17. Reds (19)

18. Giants (17)

19. Padres (NR)

20. Rangers (18)