| Starter | Tm | Tier | Game |
|---|---|---|---|
| Frank Viola | NYN | 2.71 | 199004270_NYN_HOU |
| John Tudor | SLN | 2.6 | 199004280_SLN_SFN |
| Tim Belcher | LAN | 2.55 | 199004260_SLN_LAN |
| Mark Gubicza | KCA | 1.99 | 199004260_KCA_MIL |
| Dave Stieb | TOR | 1.4 | 199004260_CLE_TOR |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Jim Clancy | HOU | -3.7 | 199004260_HOU_ATL |
| Oil Can Boyd | WAS | -3.27 | 199004280_WAS_CIN |
| Melido Perez | CHA | -2.27 | 199004260_CHA_TEX |
| Jack Morris | DET | -2.14 | 199004270_MIL_DET |
| Terry Mulholland | PHI | -1.74 | 199004280_PHI_ATL |
Based on accumulated WAA for this season up to 1990-04-28.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +001+ | 2.03 | Dennis Cook | 27.3 | PHI |
| +002+ | 1.86 | John Tudor | 28 | SLN |
| +003+ | 1.83 | Chuck Finley | 28 | ANA |
| +007+ | 1.53 | Frank Viola | 27.3 | NYN |
| +009+ | 1.48 | Chris Bosio | 26 | MIL |
| +010+ | 1.48 | Mike Morgan | 23.7 | LAN |
| +013+ | 1.45 | Zane Smith | 28 | WAS |
| +015+ | 1.4 | Jack Armstrong | 25.7 | CIN |
| +017+ | 1.36 | Dennis Martinez | 27 | WAS |
| +019+ | 1.3 | Ed Whitson | 24 | SDN |
| +021+ | 1.27 | Bob Welch | 25 | OAK |
| XXXXX | 1.22 | Jim Deshaies | 26 | HOU |
| XXXXX | 1.17 | Dave Stewart | 26.3 | OAK |
| XXXXX | 1.07 | Kirk McCaskill | 17 | ANA |
| XXXXX | 1.05 | Nolan Ryan | 28 | TEX |
| XXXXX | 1.02 | Ramon Martinez | 28 | LAN |
| XXXXX | 0.95 | Mike LaCoss | 27.7 | SFN |
| XXXXX | 0.94 | Brian Holman | 27 | SEA |
| XXXXX | 0.91 | Tom Gordon | 17 | KCA |
| XXXXX | 0.86 | Pascual Perez | 14 | NYA |
| XXXXX | 0.84 | Atlee Hammaker | 24 | SFN |
| XXXXX | 0.83 | Mark Langston | 19 | ANA |
| XXXXX | 0.83 | Tom Filer | 14 | MIL |
| XXXXX | 0.81 | Dave Stieb | 23 | TOR |
| XXXXX | 0.8 | Dan Petry | 13.7 | DET |
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