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. Below are the final rankings through the Thursday, July 21st games: The rankings from last week are in parenthesizes 1. (1) New York Yankees - 4.29 The Yankees have held the top spot for quite a while, but they have just one win against the first-place Red Sox this season. 2. (2) Boston Red Sox - 4.16 The Red Sox will not be looking up at anyone for much longer if they add some pitching prior to the July 31 non-waiver trade deadline. 3. (4) Texas Rangers - 4.02 Coming off the longest winning streak in baseball this season, the Rangers were only able to jump up one spot as they leapfrogged the Phillies. 4. (3) Philadelphia Phillies - 3.91 Philadelphia is tied with San Francisco for the largest first-place advantage (four games) heading into the weekend. The addition of Roy Oswalt (disabled list) will only bolster their playoff chances. 5. (5) Atlanta Braves - 3.69 The Braves, second-place in the NL East and leading the Wild Card race, would hold down the top spot if they called the NL West home. 6. (6) Los Angeles Angels - 3.63 Despite the recent run of the Rangers, the Angels are just three games back in the AL West. 7. (9) San Francisco Giants - 3.59 If the Giants add a bat (see: Beltran, Carlos), they will improve their OPS (ranked 26th) and therefore their Ospera ranking. 8. (7) St. Louis Cardinals - 3.57 The Cardinals have slid down this list because of their pitching staff. 9. (8) Tampa Bay Rays - 3.49 They kept their playoff hopes alive by splitting a series with the Yankees this week. Still, they are 7.5 games back of the Red Sox and 5.5 back of the Bombers. 10. (10) Pittsburgh Pirates - 3.41 The next 10 games will determine whether or not Pittsburgh is for real and ready to make a playoff run. They will host the Cardinals before traveling to Atlanta and Philadelphia. 11. (13) New York Mets - 3.33 12. (14) Milwaukee Brewers - 3.31 T13. (12) Toronto Blue Jays - 3.29 -- (15) Oakland Athletics - 3.29 15. (11) Arizona Diamondbacks - 3.26 Biggest Jump: T16. (19) Colorado Rockies - 3.23 -- (20) Chicago White Sox - 3.23 18. (18) Detroit Tigers - 3.22 T19. (21) Cincinnati Reds - 3.21 -- (22) San Diego Padres - 3.21 Biggest Drop: 21. (16) Washington Nationals - 3.16 22. (17) Cleveland Indians - 3.12 23. (23) Florida Marlins - 2.98 24. (24) Los Angeles Dodgers - 2.92 25. (25) Seattle Mariners - 2.78 26. (26) Kansas City Royals - 2.67 27. (28) Minnesota Twins - 2.46 28. (27) Chicago Cubs - 2.44 29. (29) Baltimore Orioles - 2.40 30. (30) Houston Astros - 2.30