10 games in the PremovedPrep archive. Games as White.
| White | Black | Result | ECO | Event | Date |
|---|---|---|---|---|---|
| Costello, John | Henry Marwa Michael | 0-1 | E90 | Olymp 2026 Open | 2026-09-26 |
| Costello, John | Delrieu, Marc | 1/2-1/2 | D08 | Olymp 2026 Open | 2026-09-25 |
| Costello, John | MBOULA MBOUMBA, Jerome | 0-1 | D31 | Olymp 2026 Open | 2026-09-21 |
| Costello, John | Germanovs, Georgijs | 0-1 | E12 | Olymp 2026 Open | 2026-09-16 |