| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bret Saberhagen | KCA | 8.65 | 198909221_SEA_KCA |
| Mike Moore | OAK | 5.31 | 198909230_OAK_MIN |
| Scott Garrelts | SFN | 4.73 | 198909220_HOU_SFN |
| Bert Blyleven | ANA | 4.01 | 198909232_ANA_CLE |
| Bruce Hurst | SDN | 3.52 | 198909220_SDN_LAN |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bobby Witt | TEX | -5.72 | 198909230_CHA_TEX |
| Walt Terrell | NYA | -3.3 | 198909220_NYA_BAL |
| Don August | MIL | -2.08 | 198909230_TOR_MIL |
| Mike Witt | ANA | -1.91 | 198909231_ANA_CLE |
| Randy Johnson | SEA | -1.75 | 198909210_SEA_TEX |
Based on accumulated WAA for this season up to 1989-09-23.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +002+ | 8.57 | Bret Saberhagen | 246 | KCA |
| +006+ | 6.92 | Orel Hershiser | 239 | LAN |
| +009+ | 6.02 | Scott Garrelts | 186.7 | SFN |
| +013+ | 5.77 | Mike Moore | 235 | OAK |
| +015+ | 5.6 | Ed Whitson | 220 | SDN |
| +017+ | 5.32 | Chuck Finley | 187.3 | ANA |
| +016+ | 5.32 | Mark Langston | 244.3 | TOT |
| +018+ | 5.3 | Bruce Hurst | 238.3 | SDN |
| +023+ | 5.02 | Rick Reuschel | 204.3 | SFN |
| +028+ | 4.79 | Chris Bosio | 235 | MIL |
| +029+ | 4.78 | Bert Blyleven | 232 | ANA |
| +032+ | 4.62 | Bryn Smith | 203.7 | WAS |
| +037+ | 4.2 | Kirk McCaskill | 198.7 | ANA |
| +039+ | 4.16 | Mark Gubicza | 255.7 | KCA |
| +040+ | 4.14 | Jose DeLeon | 233 | SLN |
| +043+ | 4.03 | Doug Drabek | 236.3 | PIT |
| +046+ | 3.95 | Mike Morgan | 152.3 | LAN |
| +048+ | 3.93 | John Smiley | 205.3 | PIT |
| +049+ | 3.89 | Joe Magrane | 227.7 | SLN |
| +050+ | 3.87 | Greg Maddux | 230 | CHN |
| +056+ | 3.73 | Tim Belcher | 221.3 | LAN |
| +058+ | 3.64 | John Cerutti | 198.7 | TOR |
| +060+ | 3.54 | Todd Burns | 93.7 | OAK |
| +064+ | 3.46 | Sid Fernandez | 202 | NYN |
| +074+ | 3.09 | Roger Clemens | 237.7 | BOS |
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