| Starter | Tm | Tier | Game |
|---|---|---|---|
| Orel Hershiser | LAN | 6.99 | 198909080_LAN_SDN |
| Bret Saberhagen | KCA | 6.44 | 198909090_MIN_KCA |
| Mike Moore | OAK | 4.45 | 198909090_NYA_OAK |
| Bert Blyleven | ANA | 3.75 | 198909080_BOS_ANA |
| Rick Reuschel | SFN | 3.34 | 198909070_SFN_ATL |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bobby Witt | TEX | -5.24 | 198909072_BAL_TEX |
| Melido Perez | CHA | -3.77 | 198909090_CHA_DET |
| Jim Clancy | HOU | -2.62 | 198909070_SDN_HOU |
| Andy Hawkins | NYA | -2.58 | 198909080_NYA_OAK |
| Bob Walk | PIT | -1.9 | 198909070_PIT_WAS |
Based on accumulated WAA for this season up to 1989-09-09.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +004+ | 7.08 | Orel Hershiser | 226 | LAN |
| +005+ | 6.81 | Bret Saberhagen | 223 | KCA |
| +008+ | 6.11 | Mike Moore | 217 | OAK |
| +009+ | 5.91 | Scott Garrelts | 164.7 | SFN |
| +011+ | 5.75 | Mark Gubicza | 244.7 | KCA |
| +015+ | 5.53 | Chris Bosio | 226 | MIL |
| +019+ | 5.15 | Bert Blyleven | 210 | ANA |
| +020+ | 5.15 | Chuck Finley | 176.3 | ANA |
| +022+ | 4.95 | Ed Whitson | 209.7 | SDN |
| +027+ | 4.4 | Mark Langston | 224.3 | TOT |
| +030+ | 4.3 | Rick Reuschel | 182.3 | SFN |
| +034+ | 4.11 | Sid Fernandez | 183 | NYN |
| +035+ | 3.98 | Bob Welch | 183 | OAK |
| +040+ | 3.88 | Bryn Smith | 190.7 | WAS |
| +042+ | 3.82 | John Smoltz | 209.7 | ATL |
| +043+ | 3.8 | Bruce Hurst | 213.3 | SDN |
| +044+ | 3.7 | Mike Morgan | 149.3 | LAN |
| +045+ | 3.66 | Jose DeLeon | 221 | SLN |
| +048+ | 3.6 | John Cerutti | 185 | TOR |
| +051+ | 3.56 | Dennis Martinez | 214 | WAS |
| +057+ | 3.4 | Joe Magrane | 208.3 | SLN |
| +059+ | 3.35 | Greg Maddux | 209.3 | CHN |
| +064+ | 3.26 | Kirk McCaskill | 176.3 | ANA |
| +069+ | 3.05 | Doug Drabek | 216.7 | PIT |
| +075+ | 2.92 | Mike Scott | 210 | HOU |
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