| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bret Saberhagen | KCA | 6.44 | 198909090_MIN_KCA |
| Scott Garrelts | SFN | 5.06 | 198909110_ATL_SFN |
| Mike Moore | OAK | 4.45 | 198909090_NYA_OAK |
| John Smiley | PIT | 3.63 | 198909100_PIT_NYN |
| Ed Whitson | SDN | 3.22 | 198909090_LAN_SDN |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Dave Schmidt | BAL | -5.09 | 198909100_BAL_TEX |
| Melido Perez | CHA | -3.77 | 198909090_CHA_DET |
| Bob Knepper | SFN | -2.72 | 198909100_SFN_HOU |
| Randy Johnson | SEA | -1.54 | 198909100_MIL_SEA |
| Jeff Robinson | PIT | -1.28 | 198909090_PIT_NYN |
Based on accumulated WAA for this season up to 1989-09-11.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +004+ | 7.07 | 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 |
| +010+ | 5.74 | Mark Gubicza | 244.7 | KCA |
| +016+ | 5.51 | Chris Bosio | 226 | MIL |
| +018+ | 5.28 | John Smiley | 196 | PIT |
| +019+ | 5.08 | Chuck Finley | 176.3 | ANA |
| +020+ | 5.07 | Bert Blyleven | 210 | ANA |
| +023+ | 4.94 | Ed Whitson | 209.7 | SDN |
| +030+ | 4.39 | Mark Langston | 231.7 | TOT |
| +032+ | 4.29 | Rick Reuschel | 182.3 | SFN |
| +034+ | 4.1 | Sid Fernandez | 190.3 | NYN |
| +037+ | 3.97 | Bob Welch | 183 | OAK |
| +039+ | 3.88 | Bryn Smith | 190.7 | WAS |
| +040+ | 3.83 | John Smoltz | 209.7 | ATL |
| +043+ | 3.79 | Bruce Hurst | 213.3 | SDN |
| +044+ | 3.69 | Mike Morgan | 149.3 | LAN |
| +046+ | 3.66 | Jose DeLeon | 221 | SLN |
| +047+ | 3.59 | Kirk McCaskill | 183.3 | ANA |
| +048+ | 3.58 | John Cerutti | 185 | TOR |
| +050+ | 3.56 | Dennis Martinez | 214 | WAS |
| +057+ | 3.4 | Joe Magrane | 208.3 | SLN |
| +059+ | 3.35 | Greg Maddux | 216.7 | CHN |
| +073+ | 3.05 | Doug Drabek | 216.7 | PIT |
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