Not enough days in 1991 season to compile WAA record.
| Date | Rank | WAA | TeamID |
|---|---|---|---|
| 19910418 | XXXXX | 0.20 | PHI |
| 19910502 | XXXXX | 0.34 | PHI |
| 19910516 | XXXXX | 0.34 | PHI |
| 19910530 | XXXXX | 0.52 | PHI |
| 19910613 | XXXXX | 0.56 | PHI |
| 19910627 | XXXXX | 0.89 | PHI |
| 19910714 | XXXXX | 0.97 | PHI |
| 19910728 | XXXXX | 1.18 | PHI |
| 19910811 | +094+ | 2.15 | PHI |
| 19910825 | +072+ | 2.73 | PHI |
| 19910908 | +070+ | 2.98 | PHI |
| 19910922 | +081+ | 3.15 | PHI |
| 19911006 | +083+ | 3.16 | PHI |
Mitch Williams Post Season Games
| Rank | WAA | IP | ERA | Gs | Gr | Tm |
|---|---|---|---|---|---|---|
| XXXXX | 0.08 | 1 | 0 | 0 | 2 | CHN |
| XXXXX | -0.8 | 8 | 7.88 | 0 | 7 | PHI |
| XXXXX | -0.72 | 9 | 7 | 0 | 0 | TOT |
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