The Opsera is a statistic I created in order to rank teams by how well they hit (OPS) and pitch (ERA). In order to determine a team's Opsera, I take their OPS, move the decimal point over one place to the right and then subtract the team's ERA from that number. * Previous week's ranking in parenthesis. 1. Toronto Blue Jays: 4.33 (2nd) Jason Frasor has a 0.64 ERA and four wins coming out of the bullpen; Jose Arredondo of the Angels led all relievers with 10 wins last season while four separate relievers have recorded as many as 12 in a season since 1990. 2. Los Angeles Dodgers: 4.28 (1st) Jonathan Broxton has a 1.50 ERA, 15.0 K/9 rate and nine saves. 3. New York Mets: 4.06 (4th) The Mets have hit for an OPS of .971 against lefties this season. 4. Kansas City Royals: 4.01 (3rd) Alberto Callaspo keeps on hitting; the second baseman has a .919 OPS with 15 doubles. 5. Milwaukee Brewers: 3.92 (6th) Despite losing Sabathia and Sheets, the Brewers pitching staff has been surprisingly consistent, with all five starters posting ERAs under 5.00, a rare feat so far in 2009. 6. Texas Rangers: 3.75 (10th) The Rangers have a 3.10 ERA during the month of May, which is not surprisingly the best in baseball. They also happen to have the fewest strikeouts with just 82 in 145 innings. 7. Detroit Tigers: 3.61 (7th) Edwin Jackson (2.42 ERA) and Rick Porcello (3.86) are clearly pushing Justin Verlander for having the best young arm in Detroit. 8. St. Louis Cardinals: 3.50 (5th) Ryan Ludwick is showing as much power as he did last season, hitting eight homers in 106 at bats. 9. Boston Red Sox: 3.35 (9th) Jason Bay is hitting one homer for every 12 at bats, a significant jump from his career average of 18.2. 10. Cincinnati Reds: 3.35 (12th) Johnny Cueto was overshadowed last season by Edinson Volquez, but the youngster has a 1.93 ERA and 1.01 WHIP through 46.2 innings. 11. Atlanta Braves: 3.22 (8th) Jair Jurrjens has been excellent again this season, with a 2.06 ERA and 1.17 WHIP despite a modest 4.5 K/9 rate. He has left 84.9% of his baserunners stranded. 12. Pittsburgh Pirates: 3.19 (17th) The Pirates currently have the best UZR defense in baseball. 13. Tampa Bay Rays: 3.18 (11th) Scott Kazmir and Andy Sonnanstine have struggled through their first eight/nine starts with ERAs of 6.97 and 7.43 respectively. 14. Chicago Cubs: 3.16 (15th) A weakness last season, the Cubs are hitting for an OPS of .774 against righties. 15. Colorado Rockies: 2.94 (13th) The Rockies are eight games below .500 despite having a dead even run differential. 16. New York Yankees: 2.87 (26th) A.J. Burnett is giving up an OPS of .499 in innings 1-3, but .927 in innings 4-6 and 1.079 in innings 7-9. The drop in his K/BB rate (1.72 from his 2.69 mark last year) is the likely culprit, as being too fine catches up with him later in his outings. 17. Los Angeles Angels: 2.82 (16th) The Angels really could use Mike Napoli's bat in the lineup on a daily basis; the catcher is hitting .324/.420/.569 with six homers in 102 at bats. 18. Seattle Mariners: 2.71 (21st) Russell Branyan has picked up where he left off last season in limited duty with the Brewers by hitting for an OPS of .969 and nine homers. 19. Houston Astros: 2.66 (14th) Wandy Rodriguez continues his excellent 2009, with a 1.90 ERA, 1.00 WHIP and 8.3 K/9 rate. 20. Arizona Diamondbacks: 2.65 (18th) Doug Davis (3.22 ERA) and Max Scherzer (3.35 ERA) have done everything they can to help out Dan Haren while Brandon Webb sits on the DL. 21. Philadelphia Phillies: 2.61 (25th) The Phillies' starters are posting a 6.35 ERA, which is unsurprisingly last in baseball. 22. San Francisco Giants: 2.58 (20th) Three of the Giants' regulars (Bengie Molina, Pablo Sandoval and Fred Lewis) have an OPS over .800, but their other five are all below .730 (Aaron Rowand, Randy Winn, Edgar Renteria, Emmanuel Burriss and Travis Ishikawa). 23. Minnesota Twins: 2.45 (29th) With eight strikeouts, zero walks and no runs allowed until the seventh inning, Kevin Slowey deserved a better fate on Sunday at Yankee Stadium. 24. Florida Marlins: 2.37 (19th) The leadoff position has an on base percentage of just .290, which is 26th in the MLB. 25. San Diego Padres: 2.31 (27th) After a difficult April (5.75 ERA), Jake Peavy has straightened himself out in May (2.14 ERA), although it hasn't resulted in any wins. 26. Washington Nationals: 2.28 (24th) The Nationals have had the MLB's best offense in May, with an .846 OPS and 98 runs scored. 27. Oakland Athletics: 2.26 (23rd) Matt Holliday has an OPS of .741 at home and .669 on the road. 28. Baltimore Orioles: 2.21 (28th) Orioles' catchers are hitting .206/.288/.328, which is sure to improve dramatically as soon as Matt Wieters is called up. 29. Chicago White Sox: 2.19 (22nd) Carlos Quentin is batting .186/.214/.185 during the month of May. 30. Cleveland Indians: 2.12 (30th) It is difficult to zero in on what exactly Grady Sizemore is doing wrong, but he does have home/away OPS splits of .561/.829.