| Starter | Tm | Tier | Game |
|---|---|---|---|
| Wilbur Wood | CHA | 15.57 | 197305201_MIN_CHA |
| Tom Seaver | NYN | 7.04 | 197305180_PIT_NYN |
| Bob Gibson | SLN | 2.38 | 197305201_SLN_WAS |
| Joe Coleman | DET | 2.26 | 197305190_DET_MIL |
| Bert Blyleven | MIN | 2.17 | 197305190_MIN_CHA |
| Starter | Tm | Tier | Game |
|---|---|---|---|
| Ken Brett | PHI | -2.62 | 197305191_CHN_PHI |
| Ron Reed | ATL | -2.58 | 197305180_LAN_ATL |
| Reggie Cleveland | SLN | -2.24 | 197305202_SLN_WAS |
| Bill Champion | MIL | -2.12 | 197305180_MIL_NYA |
| Rich Gossage | CHA | -1.87 | 197305180_MIN_CHA |
Based on accumulated WAA for this season up to 1973-05-20.
| Rank | WAA | Name | IP | Tm |
|---|---|---|---|---|
| +001+ | 4.25 | Ken Holtzman | 87.7 | OAK |
| +002+ | 4.02 | Wilbur Wood | 109 | CHA |
| +004+ | 3.51 | Bill Singer | 80.7 | ANA |
| +005+ | 3.43 | Tom Seaver | 74.3 | NYN |
| +009+ | 2.61 | Rick Reuschel | 59 | CHN |
| +011+ | 2.57 | Ron Bryant | 68.7 | SFN |
| +012+ | 2.38 | Joe Coleman | 77 | DET |
| +015+ | 2.29 | Jim Perry | 68.3 | DET |
| +016+ | 2.24 | Jim Palmer | 60.7 | BAL |
| +017+ | 2.19 | Paul Splittorff | 79.3 | KCA |
| +019+ | 2.09 | Gaylord Perry | 82.7 | CLE |
| +023+ | 2.02 | Jack Billingham | 77.7 | CIN |
| +022+ | 2.02 | Jerry Koosman | 57.3 | NYN |
| +025+ | 1.94 | Nolan Ryan | 82 | ANA |
| +026+ | 1.93 | Dave McNally | 69.7 | BAL |
| +029+ | 1.85 | Doyle Alexander | 53.3 | BAL |
| +033+ | 1.71 | Bill Greif | 51.7 | SDN |
| +034+ | 1.69 | Rudy May | 51 | ANA |
| +035+ | 1.66 | Don Sutton | 72 | LAN |
| +039+ | 1.63 | Jerry Reuss | 72.3 | HOU |
| +042+ | 1.57 | Bill Lee | 58 | BOS |
| +044+ | 1.53 | Ross Grimsley | 66.7 | CIN |
| +052+ | 1.33 | Rollie Fingers | 29 | OAK |
| +055+ | 1.26 | Dave Roberts | 57.3 | HOU |
| XXXXX | 1.25 | Rogelio Moret | 14.7 | BOS |
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