| Starter | Tm | Tier | Game |
|---|---|---|---|
| Scott Garrelts | SFN | 5.06 | 198909110_ATL_SFN |
| Mark Gubicza | KCA | 4.89 | 198909120_TEX_KCA |
| Chris Bosio | MIL | 4.02 | 198909120_MIL_OAK |
| John Smiley | PIT | 3.63 | 198909100_PIT_NYN |
| Mark Langston | WAS | 2.87 | 198909110_WAS_CHN |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Dave Schmidt | BAL | -5.09 | 198909100_BAL_TEX |
| Bob Knepper | SFN | -2.72 | 198909100_SFN_HOU |
| Walt Terrell | NYA | -2.46 | 198909120_NYA_ANA |
| David West | MIN | -2.35 | 198909120_TOR_MIN |
| Bob Walk | PIT | -2.14 | 198909120_PIT_SLN |
Based on accumulated WAA for this season up to 1989-09-12.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +004+ | 7.08 | Orel Hershiser | 226 | LAN |
| +006+ | 6.8 | Bret Saberhagen | 223 | KCA |
| +008+ | 6.18 | Scott Garrelts | 172.7 | SFN |
| +009+ | 6.09 | Mike Moore | 217 | OAK |
| +015+ | 5.46 | Mark Gubicza | 248.7 | KCA |
| +017+ | 5.29 | John Smiley | 196 | PIT |
| +019+ | 5.07 | Chuck Finley | 176.3 | ANA |
| +020+ | 5.07 | Bert Blyleven | 210 | ANA |
| +022+ | 4.94 | Ed Whitson | 209.7 | SDN |
| +023+ | 4.85 | Chris Bosio | 228 | MIL |
| +026+ | 4.6 | Rick Reuschel | 188.3 | SFN |
| +028+ | 4.57 | Bruce Hurst | 222.3 | SDN |
| +032+ | 4.49 | Bryn Smith | 197.7 | WAS |
| +035+ | 4.41 | Mark Langston | 231.7 | TOT |
| +037+ | 4.11 | Sid Fernandez | 190.3 | NYN |
| +041+ | 3.83 | John Smoltz | 209.7 | ATL |
| +042+ | 3.69 | Mike Morgan | 149.3 | LAN |
| +045+ | 3.66 | Jose DeLeon | 221 | SLN |
| +047+ | 3.59 | John Cerutti | 185 | TOR |
| +048+ | 3.58 | Kirk McCaskill | 183.3 | ANA |
| +050+ | 3.58 | Dennis Martinez | 214 | WAS |
| +053+ | 3.5 | Joe Magrane | 214.3 | SLN |
| +061+ | 3.35 | Greg Maddux | 216.7 | CHN |
| +063+ | 3.24 | Bob Welch | 186.7 | OAK |
| +064+ | 3.19 | Todd Burns | 89.7 | OAK |
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