| 26 ago 2026 | Nehmert, Ulrich 2256 | Siebenhaar, Erich 2070 | 1-0 | A42 Defensa Moderna: Kotov Variation | 23. Rheinland-Pfalz Senioren Open | 29 | Ver |
| 25 ago 2026 | Siebenhaar, Erich 2070 | Paus, Franz 2010 | 1-0 | B03 Defensa Alekhine: Exchange Variation, Voronezh Variation | 23. Rheinland-Pfalz Senioren Open | 46 | Ver |
| 11 ago 2026 | Pirrot, Dieter 2312 | Siebenhaar, Erich 2070 | 1-0 | B06 Defensa Moderna: Modern Pterodactyl | 23. Rheinland-Pfalz Senioren Open | 13 | Ver |
| 26 sep 2025 | Siebenhaar, Erich 2087 | Gruzmann, Boris 2088 | ½-½ | C44 Apertura Ponziani: Jaenisch Counterattack | German Senior Team Championship of the State Associations | S65 | 15 | Ver |
| 25 sep 2025 | Haubt, Georg 2051 | Siebenhaar, Erich 2087 | 0-1 | A40 Horwitz Defense | German Senior Team Championship of the State Associations | S65 | 50 | Ver |