Not enough days in 1931 season to compile WAA record.
| Date | Rank | WAA | TeamID |
|---|---|---|---|
| 19310510 | XXXXX | -0.71 | OAK |
| 19310524 | XXXXX | -1.05 | OAK |
| 19310607 | XXXXX | -0.69 | OAK |
| 19310621 | XXXXX | -0.23 | OAK |
| 19310705 | XXXXX | -0.42 | OAK |
| 19310719 | XXXXX | -0.45 | OAK |
| 19310802 | XXXXX | 1.04 | OAK |
| 19310816 | +079+ | 1.57 | OAK |
| 19310830 | +083+ | 1.74 | OAK |
| 19310913 | XXXXX | -0.32 | OAK |
| 19310927 | XXXXX | -0.49 | OAK |
Roy Mahaffey Post Season Games
| Rank | WAA | IP | ERA | Gs | Gr | Tm |
|---|---|---|---|---|---|---|
| XXXXX | -0.13 | 1 | 9 | 0 | 1 | OAK |
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