Can anyone topple Astros in Power Rankings?

As little intrigue as there is in the American League Wild Card race at this point -- though the resurgence of the Oakland A's, now six games behind the Mariners for the second spot, is making things slightly more interesting -- the National League, more than halfway through the season, is wide open.
None of the first-place teams in the NL have comfortable leads. The Braves and Phillies are tied. The Brewers' grasp of first place in the NL Central is anything but sturdy. And the NL West? Heck, today it's the D-backs, tomorrow it could be the Dodgers. And by the All-Star break, the Rockies and the Giants could have inched their way to the top.
That makes for a truly wild scene in the race for the Wild Cards. Through Monday, the NL Wild Card race featured five teams at the .500 mark or better, and the worst of the bunch -- the 45-45 Nationals -- are only 5 1/2 games back. That leaves just five teams in the entire league that, at this point, are below .500 and therefore can't realistically be considered contenders.
On to the Power Rankings ...
Biggest jump: The Reds, not ranked last week or in any of our Power Rankings this season, are debuting at No. 19, and, based on their past six weeks or so, they could expect to keep climbing. The Reds have won 15 of 21, including their opener in Cleveland on Monday. After a 3-15 start, the Reds have played better-than-.500 ball, thanks mostly to their pitching catching up to an offense that has been pretty steady all year. From June 8 through Sunday's game, the Reds had the fifth-lowest ERA in the NL at 3.84. Since May 18, the Reds' .765 OPS is fourth-highest in the league.

Biggest drop: Not a lot of movement this week. The biggest drop was only two spots, by three teams: the Mariners (No. 5 to No. 7), the D-backs (No. 8 to No. 10) and the Angels (No. 15 to No. 17). After a good start to the season, the Angels are struggling to stay over .500, and over their past 15 games, they've lost 10 times. During that stretch, they've scored 48 runs (3.2 per game).
Power Rankings Top 5:
1. Astros (1 last week)
During a six-game winning streak that ended with a 2-0 loss to the A's on Monday, the Astros scored 39 runs on 59 hits. First-time All-Star Alex Bregman has reached base safely in 16 straight games, logging 13 extra-base hits and 15 RBIs during that streak. Also, the Astros have continued winning, even without Carlos Correa, who's out with a sore back. Since Correa last played on June 25, Houston has won nine of 13 games.
2. Red Sox (3)
Boston, 14-5 since June 19, is on a roll offensively. All-Star Final Vote nominee Andrew Benintendi has reached base safely in 15 of his last 20 plate appearances, with eight runs scored in those five games. Xander Bogaerts has reached base safely in 14 of his last 25 plate appearances, recording two home runs and 10 RBIs. And All-Star Mookie Betts has reached base safely in 13 straight games, hitting .373 (19-for-51) with 14 runs over that stretch.

3. Yankees (2)
Since they were swept by the Rays two weeks ago, the Yankees are 9-5 and have managed to stay within striking distance of the Red Sox in a still-tight AL East race. Giancarlo Stanton, a Final Vote nominee, has been great of late: In his past 15 games, he's hitting .377 (23-for-61) with four homers and 11 RBIs.

4. Brewers (4)
The Brewers lost on Monday, but with several games remaining until the All-Star break, it's a safe bet that Milwaukee -- currently 54-37 -- will surpass the '79 club (54-38) and set a record for the most wins pre-All-Star. Despite their extra-inning defeat in Miami, the Brewers have been on a nice roll, winning six of their past eight, while posting a 2.95 ERA.
5. Cubs (7)
Despite some rough patches, the Cubs appear to be getting back on track. Entering their game in San Francisco on Monday, the Cubs were slashing .341/.410/.534 with 86 runs scored -- 7.8 per game -- over their prior 11 contests, going 9-2 over that stretch. Offensively, Kyle Schwarber has really turned it on, reaching base safely in eight straight games, slashing .391/.533/.739 (9-for-23) with nine runs scored.

The rest of the Top 20:
6. Indians (6 last week)

7. Mariners (5)
   
8. Phillies (11)
   
9. Braves (9)
   
10. D-backs (8)
    
11. Dodgers (10)
    
12. Cardinals (13)
    
13. Nationals (12)
    
14. A's (14)
    
15. Rays (17)
    
16. Giants (16)
    
17. Angels (15)
    
18. Rockies (19)
    
19. Reds (NR)
    
20. Blue Jays (20)