The Opsera is a statistic RealGM Executive Editor Chris Reina created in order to objectively rank teams by how well they hit (OPS) and pitch (ERA). 

In order to determine the Opsera rating for each, we take their OPS, multiply that number by 10 to move the decimal point over one place to the right and then subtract their ERA from that number.  

All statistics are through Wednesday, Sept. 4.

Rankings from last week are in parenthesizes.

1. (1) Detroit Tigers – 4.17

The Tigers and Red Sox ended their three-game series with the same OPS (.789).

2. (4) Boston Red Sox – 4.15

Boston appears to have the AL East locked up, but this weekend's series against New York gives them a chance to deliver a fatal blow to their rival's playoff hopes.

3. (2) Atlanta Braves – 4.13

Only three teams have a higher run differential than the Braves (+133).

4. (3) Los Angeles Dodgers – 4.03 

The Dodgers were in the bottom third of these rankings in late June.

5. (6) Pittsburgh Pirates – 3.90

They will finish above .500 for the first time since George H.W. Bush was in office, but they have much loftier goals.

6. (7) Cincinnati Reds – 3.80

7. (8) Texas Rangers – 3.76 

8. (5) St. Louis Cardinals – 3.75

9. (10) Oakland Athletics – 3.69

10. (9) Tampa Bay Rays – 3.61

11. (12) Kansas City Royals – 3.46

12. (15) Washington Nationals – 3.34

T13. (11) Arizona Diamondbacks – 3.28

-- (13) Cleveland Indians – 3.28

15. (14) Baltimore Orioles – 3.20

16. (T17) Colorado Rockies – 3.19

17. (16) Milwaukee Brewers – 3.16

18. (19) New York Yankees – 3.13

T19. (T17) New York Mets – 3.11

-- (22) Los Angeles Angels – 3.11

21. (20) Chicago Cubs – 3.01

22. (23) Toronto Blue Jays – 2.97

23. (21) Chicago White Sox – 2.93

24. (24) San Francisco Giants – 2.86

25. (26) San Diego Padres – 2.75

26. (27) Minnesota Twins – 2.73

27. (25) Seattle Mariners – 2.70

28. (28) Philadelphia Phillies – 2.61

29. (29) Miami Marlins – 2.54

30. (30) Houston Astros – 1.98