| Team | Tm | Tier | Game |
|---|---|---|---|
| Oakland Athletics | OAK | 6.16 | 199009210_DET_OAK |
| Detroit Tigers | DET | 2.2 | 199009190_DET_ANA |
| Pittsburgh Pirates | PIT | 1.07 | 199009190_PIT_CHN |
| Cincinnati Reds | CIN | 1.06 | 199009200_CIN_HOU |
| Chicago White Sox | CHA | 0.91 | 199009210_CHA_SEA |
| Team | Tm | Tier | Game |
|---|---|---|---|
| Atlanta Braves | ATL | -6.21 | 199009210_HOU_ATL |
| Chicago Cubs | CHN | -3.62 | 199009200_PIT_CHN |
| Houston Astros | HOU | -1.84 | 199009210_HOU_ATL |
| Minnesota Twins | MIN | -1.38 | 199009190_KCA_MIN |
| Boston Red Sox | BOS | -0.76 | 199009190_BOS_BAL |
Based on accumulated WAA for this season up to 1990-09-21.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +021+ | 5.19 | Dennis Eckersley | 69.7 | OAK |
| +025+ | 5.05 | Bill Swift | 123.3 | SEA |
| +029+ | 4.74 | Larry Andersen | 89.7 | TOT |
| +040+ | 4.2 | Rob Dibble | 91.3 | CIN |
| +046+ | 3.59 | Bobby Thigpen | 81.7 | CHA |
| +048+ | 3.54 | Greg Harris | 110.7 | SDN |
| +052+ | 3.35 | Edwin Nunez | 78 | DET |
| +055+ | 3.3 | Jeff Montgomery | 89 | KCA |
| +061+ | 3.27 | Randy Myers | 81 | CIN |
| +060+ | 3.27 | Gene Nelson | 69.3 | OAK |
| +066+ | 3.09 | Lee Smith | 80.7 | TOT |
| +068+ | 3.06 | Tom Henke | 69.3 | TOR |
| +069+ | 2.96 | Brad Arnsberg | 58.3 | TEX |
| +080+ | 2.59 | Jay Howell | 61 | LAN |
| +081+ | 2.56 | Doug Jones | 78.3 | CLE |
| +084+ | 2.53 | Dan Schatzeder | 67.7 | TOT |
| +086+ | 2.42 | Barry Jones | 71 | CHA |
| +088+ | 2.4 | Gregg Olson | 70.7 | BAL |
| +091+ | 2.38 | Craig Lefferts | 76.3 | SDN |
| +096+ | 2.33 | John Franco | 65 | NYN |
| +106+ | 2.14 | Eric Plunk | 70 | NYA |
| +108+ | 2.09 | Bill Landrum | 65 | PIT |
| +113+ | 1.98 | Mike Henneman | 90.7 | DET |
| +118+ | 1.9 | Paul Gibson | 96.7 | DET |
| +127+ | 1.8 | Bob Patterson | 92 | PIT |
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