25 games in the PremovedPrep archive. Games as White.
| White | Black | Result | ECO | Event | Date |
|---|---|---|---|---|---|
| Mertens, Klaus | Stuemer, Paul | 1/2-1/2 | E60 | Round 9: Mertens, Klaus - Stuemer, Paul | 2026-08-26 |
| Mertens, Klaus | Schaefer, Bernd | 1/2-1/2 | A05 | Round 8: Mertens, Klaus - Schaefer, Bernd | 2026-08-25 |
| Mertens, Klaus | Tozaki, Halil | 1-0 | A05 | Round 6: Mertens, Klaus - Tozaki, Halil | 2026-08-23 |
| Mertens, Klaus | Busic, Nedjeljko | 1/2-1/2 | A05 | Round 4: Mertens, Klaus - Busic, Nedjeljko | 2026-08-21 |
| Mertens, Klaus | Best, Ingeborg | 1-0 | A13 | Round 2: Mertens, Klaus - Best, Ingeborg | 2026-08-19 |
| Mertens, Klaus | Meyer, Armin | 1/2-1/2 | A07 | 20. RLP-Senioren-Open | 2023-09-13 |
| Mertens, Klaus | Stuemer, Paul | 1/2-1/2 | E62 | 20. RLP-Senioren-Open | 2023-09-11 |
| Mertens, Klaus | Haubt, Georg | 1-0 | D02 | 20. RLP-Senioren-Open | 2023-09-10 |
| Mertens, Klaus | Polster, Wolfgang | 1/2-1/2 | A04 | 20. RLP-Senioren-Open | 2023-09-08 |
| Mertens, Klaus | Hesse, Rutger | 1-0 | D78 | 20. RLP-Senioren-Open | 2023-09-06 |