| Starter | Tm | Tier | Game |
|---|---|---|---|
| Orel Hershiser | LAN | 6.58 | 198908180_LAN_NYN |
| Bert Blyleven | ANA | 5.33 | 198908190_CLE_ANA |
| Chris Bosio | MIL | 5.26 | 198908170_BOS_MIL |
| Rick Reuschel | SFN | 4.22 | 198908180_SFN_PHI |
| John Cerutti | TOR | 3.17 | 198908170_TOR_BAL |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Bobby Witt | TEX | -4.15 | 198908190_TEX_CHA |
| Melido Perez | CHA | -3.51 | 198908180_TEX_CHA |
| Wes Gardner | BOS | -2.97 | 198908170_BOS_MIL |
| Jim Clancy | HOU | -1.78 | 198908180_CHN_HOU |
| Bruce Ruffin | PHI | -1.29 | 198908180_SFN_PHI |
Based on accumulated WAA for this season up to 1989-08-19.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +004+ | 5.88 | Chris Bosio | 197.7 | MIL |
| +005+ | 5.66 | Orel Hershiser | 199 | LAN |
| +007+ | 5.54 | Mike Moore | 180 | OAK |
| +009+ | 5.45 | Bert Blyleven | 186.7 | ANA |
| +010+ | 5.41 | Mark Langston | 199.3 | TOT |
| +012+ | 5.13 | Chuck Finley | 175.7 | ANA |
| +018+ | 4.59 | Rick Reuschel | 160 | SFN |
| +019+ | 4.52 | Bret Saberhagen | 182.7 | KCA |
| +024+ | 4.21 | John Smiley | 178.7 | PIT |
| +025+ | 4.19 | Bryn Smith | 164.3 | WAS |
| +026+ | 4.16 | Ed Whitson | 179 | SDN |
| +032+ | 3.83 | Greg Swindell | 153.3 | CLE |
| +033+ | 3.81 | John Smoltz | 190.3 | ATL |
| +035+ | 3.77 | John Cerutti | 164 | TOR |
| +036+ | 3.76 | Mike Scott | 173.7 | HOU |
| +038+ | 3.6 | Greg Maddux | 183 | CHN |
| +040+ | 3.52 | Mike Bielecki | 162.7 | CHN |
| +043+ | 3.48 | Mark Gubicza | 216.7 | KCA |
| +047+ | 3.42 | Sid Fernandez | 153.7 | NYN |
| +050+ | 3.35 | Joe Magrane | 181.3 | SLN |
| +049+ | 3.35 | Bruce Hurst | 196.3 | SDN |
| +052+ | 3.23 | Kevin Brown | 175 | TEX |
| +057+ | 3.15 | Mike Morgan | 137.7 | LAN |
| +060+ | 3.06 | Doug Drabek | 187.3 | PIT |
| +063+ | 2.87 | Dennis Martinez | 185.7 | WAS |
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