| Starter | Tm | Tier | Game |
|---|---|---|---|
| Orel Hershiser | LAN | 6.29 | 198909240_SDN_LAN |
| Mike Moore | OAK | 5.31 | 198909230_OAK_MIN |
| Ed Whitson | SDN | 4.19 | 198909250_CIN_SDN |
| Bert Blyleven | ANA | 4.01 | 198909232_ANA_CLE |
| Mark Langston | WAS | 3.43 | 198909230_WAS_NYN |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bobby Witt | TEX | -5.72 | 198909230_CHA_TEX |
| Jim Clancy | HOU | -2.11 | 198909240_HOU_SFN |
| Don August | MIL | -2.08 | 198909230_TOR_MIL |
| Mike Witt | ANA | -1.91 | 198909231_ANA_CLE |
| Jack Morris | DET | -1.85 | 198909240_BOS_DET |
Based on accumulated WAA for this season up to 1989-09-25.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +002+ | 8.54 | Bret Saberhagen | 246 | KCA |
| +005+ | 7.27 | Orel Hershiser | 246 | LAN |
| +009+ | 6.01 | Scott Garrelts | 186.7 | SFN |
| +012+ | 5.74 | Mike Moore | 235 | OAK |
| +016+ | 5.55 | Ed Whitson | 227 | SDN |
| +018+ | 5.28 | Mark Langston | 244.3 | TOT |
| +019+ | 5.27 | Bruce Hurst | 238.3 | SDN |
| +021+ | 5.18 | Chuck Finley | 193.3 | ANA |
| +024+ | 5.01 | Rick Reuschel | 204.3 | SFN |
| +028+ | 4.76 | Bryn Smith | 210.7 | WAS |
| +029+ | 4.75 | Bert Blyleven | 232 | ANA |
| +030+ | 4.75 | Chris Bosio | 235 | MIL |
| +039+ | 4.17 | Kirk McCaskill | 198.7 | ANA |
| +041+ | 4.12 | Mark Gubicza | 255.7 | KCA |
| +045+ | 4.01 | Doug Drabek | 236.3 | PIT |
| +047+ | 3.93 | Mike Morgan | 152.3 | LAN |
| +048+ | 3.91 | John Smiley | 205.3 | PIT |
| +049+ | 3.87 | Joe Magrane | 227.7 | SLN |
| +050+ | 3.83 | Greg Maddux | 230 | CHN |
| +055+ | 3.71 | Jose DeLeon | 238 | SLN |
| +056+ | 3.71 | Tim Belcher | 221.3 | LAN |
| +063+ | 3.44 | Sid Fernandez | 202 | NYN |
| +064+ | 3.37 | Bob Welch | 205.3 | OAK |
| +070+ | 3.13 | Todd Burns | 94 | OAK |
| +076+ | 3.06 | John Cerutti | 204.3 | TOR |
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