| Starter | Tm | Tier | Game |
|---|---|---|---|
| Ted Higuera | MIL | 4.12 | 199005010_MIL_KCA |
| Frank Viola | NYN | 3.32 | 199005020_CIN_NYN |
| Bryn Smith | SLN | 2.59 | 199005010_SLN_SDN |
| Ed Whitson | SDN | 2.1 | 199005010_SLN_SDN |
| Mark Gubicza | KCA | 1.99 | 199005030_MIL_KCA |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Oil Can Boyd | WAS | -4.27 | 199005030_ATL_WAS |
| Jack Morris | DET | -3.38 | 199005020_MIN_DET |
| Jim Clancy | HOU | -2.51 | 199005020_HOU_PHI |
| Walt Terrell | PIT | -1.96 | 199005010_PIT_LAN |
| Andy Hawkins | NYA | -1.85 | 199005010_OAK_NYA |
Based on accumulated WAA for this season up to 1990-05-03.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +001+ | 2.32 | Frank Viola | 36.3 | NYN |
| +002+ | 2.07 | Jack Armstrong | 33.3 | CIN |
| +003+ | 2.03 | Bob Welch | 34 | OAK |
| +005+ | 1.87 | John Tudor | 28 | SLN |
| +007+ | 1.82 | Dennis Cook | 34.3 | PHI |
| +006+ | 1.82 | Dave Stewart | 34 | OAK |
| +008+ | 1.81 | Chris Bosio | 32.3 | MIL |
| +009+ | 1.79 | Teddy Higuera | 27.3 | MIL |
| +012+ | 1.57 | Kirk McCaskill | 25.3 | ANA |
| +013+ | 1.57 | Ed Whitson | 32 | SDN |
| +014+ | 1.48 | Bud Black | 34.7 | CLE |
| +017+ | 1.36 | Mike Morgan | 29.7 | LAN |
| +018+ | 1.28 | Pete Smith | 28.3 | ATL |
| XXXXX | 1.24 | Jim Deshaies | 31.7 | HOU |
| XXXXX | 1.22 | Chuck Finley | 31 | ANA |
| XXXXX | 1.2 | Bryn Smith | 34.7 | SLN |
| XXXXX | 1.19 | Greg Maddux | 27.7 | CHN |
| XXXXX | 1.14 | Dennis Martinez | 35 | WAS |
| XXXXX | 1.02 | Dave Stieb | 30 | TOR |
| XXXXX | 1.01 | Doug Drabek | 30.3 | PIT |
| XXXXX | 1.01 | Erik Hanson | 30 | SEA |
| XXXXX | 1 | Ramon Martinez | 28 | LAN |
| XXXXX | 0.96 | Mark Knudson | 20.3 | MIL |
| XXXXX | 0.94 | Mike LaCoss | 27.7 | SFN |
| XXXXX | 0.91 | Mark Langston | 25 | ANA |
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