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 Sunday, May 11.

Rankings from last week are in parenthesizes.

1. (T7) Colorado Rockies – 4.53

The Rockies surged to the top spot this week thanks to two blowout wins (a combined 23-3 in victories over Texas and Cincinnati). They have scored 33 more runs than the Chicago White Sox, who are second in the Major Leagues.

2. (1) Oakland Athletics – 4.47

Opposing hitters are raking at a .220 slip against Oakland's staff, the lowest mark in the game.

3. (6) Detroit Tigers – 4.18

Miguel Cabrera was hitting .206/.275/.333 with one home run and seven RBIs on the morning on April 22. Three weeks later, he's up to .291/.333/.485 with five homers and 29 RBIs.

4. (T7) Atlanta Braves – 4.04

No team has received a higher percentage of quality starts (77.8%) from their starters than the Braves, lowering the stress on the bullpen.

5. (2) San Francisco Giants – 3.96

Losing Brandon Belt for a significant amount of time (thumb) will hurt the offense. The first baseman is among the National League leaders in home runs (9).

6. (5) Los Angeles Dodgers – 3.91

It didn't take Clayton Kershaw any time to round back into form. In two starts since coming off the DL, Kershaw has allowed three runs and tallied 18 strikeouts in 14 innings.

T7. (9) Milwaukee Brewers – 3.84

Despite losing seven of their last 11, the Brewers still have a five-game lead in the NL Central.

-- (12) Los Angeles Angels – 3.84

He's no longer in his prime, but Albert Pujols -- .276/.346/.545 -- is looking much better than he did last season.

9. (4) Washington Nationals – 3.80

Washington's middling offense has held them back early on.

10. (3) Miami Marlins – 3.79

Can the Marlins sustain this level of offensive production? They have a .739 OPS, sixth in the Majors just a season after posting a .627 mark.

11. (11) St. Louis Cardinals – 3.67

12. (10) Cincinnati Reds – 3.54

13. (13) Boston Red Sox – 3.46

14. (14) New York Yankees – 3.18

15. (24) San Diego Padres – 3.15

16. (19) Pittsburgh Pirates – 3.14

17. (22) Kansas City Royals – 3.13

18. (25) Cleveland Indians – 3.12

19. (21) Toronto Blue Jays – 3.09

20. (23) Baltimore Orioles – 3.06

21. (20) Seattle Mariners – 3.03

22. (17) Tampa Bay Rays – 2.94

23. (26) Chicago White Sox – 2.84

24. (16) Chicago Cubs – 2.71

25. (18) Philadelphia Phillies – 2.61

26. (15) Texas Rangers – 2.58

27. (28) New York Mets – 2.55

28. (27) Minnesota Twins – 2.31

29. (29) Arizona Diamondbacks – 2.10

30. (30) Houston Astros – 1.83

 

Follow @RealGMBaseball on Twitter and 'Like Us' on Facebook!