| 19 jul 2026 | Titus, Branco 2102 | Grooten, Herman 2198 | 1-0 | B12 Defensa Caro-Kann: Advance Variation, Tal Variation | Amsterdam Chess Festival 2026 - Groep A | 32 | Ver |
| 21 jun 2026 | Kooijmans, Jermo 2256 | Grooten, Herman 2177 | 0-1 | A30 Apertura Inglesa: Symmetrical Variation, Hedgehog Defense | HSG Open 2026 A | 68 | Ver |
| 21 jun 2026 | Smeets, Kobe 2324 | Grooten, Herman 2177 | 0-1 | B12 Defensa Caro-Kann: Advance Variation, Tal Variation | HSG Open 2026 A | 48 | Ver |
| 20 jun 2026 | Grooten, Herman 2177 | Albers, Sasa 2342 | 0-1 | D58 Gambito de Dama rehusado: Tartakower Defense | HSG Open 2026 A | 32 | Ver |
| 19 jun 2026 | Grooten, Tommy 2308 | Grooten, Herman 2177 | 0-1 | A05 Apertura Zukertort | HSG Open 2026 A | 51 | Ver |
| 19 jun 2026 | Grooten, Herman 2177 | Coenen, Eduard 2123 | 1-0 | A41 Robatsch Defense: Rossolimo Variation | HSG Open 2026 A | 42 | Ver |
| 17 may 2026 | Grooten, Herman 2175 | Van Meegen, Ruud 2303 | 0-1 | A07 Ataque Indio de Rey: Yugoslav Variation | Utrecht Open 2026 | Group A | 45 | Ver |
| 16 may 2026 | Ondersteijn, Niels 2382 | Grooten, Herman 2175 | ½-½ | A26 Apertura Inglesa: King's English Variation, Botvinnik System | Utrecht Open 2026 | Group A | 69 | Ver |
| 10 may 2026 | Becx, Cesar 2027 | Grooten, Herman 2175 | 0-1 | A03 Apertura Bird: Dutch Variation | Ronde 6: Becx, Cesar - Grooten, Herman | 56 | Ver |
| 10 may 2026 | Haitjema, Jarich 2044 | Grooten, Herman 2175 | 1-0 | B22 Defensa Siciliana: Delayed Alapin Variation | Ronde 5: Haitjema, Jarich - Grooten, Herman | 83 | Ver |
| 2 may 2026 | Leenhouts, Koen 2443 | Grooten, Herman 2197 | 1-0 | E20 Defensa Nimzoindia: Kmoch Variation | Open Dutch Rapid Championship 2026 | 34 | Ver |
| 11 abr 2026 | Hommerson, Paul 2236 | Grooten, Herman 2179 | 1-0 | A46 Defensa India: Knights Variation | Dutch Meesterklasse 2025/26 | 40 | Ver |
| 8 mar 2026 | Grooten, Herman 2182 | Kuipers, Stefan 2453 | 0-1 | D37 Gambito de Dama rehusado: Three Knights Variation | Meesterklasse | 57 | Ver |
| 7 feb 2026 | Van Haastert, Edwin 2379 | Grooten, Herman 2185 | 1-0 | B23 Defensa Siciliana: Closed | Dutch Meesterklasse 2025/26 | 59 | Ver |
| 29 dic 2025 | Grooten, Herman 2176 | Chua, Ethan 2089 | ½-½ | E97 Defensa India de Rey: Orthodox Variation, Aronin-Taimanov Defense | Chessfestival Groningen 2025 | Open A | 70 | Ver |
| 28 dic 2025 | Van Foreest, Machteld 2328 | Grooten, Herman 2176 | 1-0 | B91 Defensa Siciliana: Najdorf Variation, Zagreb Variation | Chessfestival Groningen 2025 | Open A | 47 | Ver |
| 28 dic 2025 | Grooten, Herman 2181 | Smeets, Kobe 2314 | ½-½ | D24 Gambito de Dama aceptado | Chessfestival Groningen 2025 | Open A | 67 | Ver |
| 27 dic 2025 | Shivika Rohilla 2048 | Grooten, Herman 2176 | 0-1 | A30 Apertura Inglesa: Symmetrical Variation, Hedgehog Defense | Chessfestival Groningen 2025 Open A | 77 | Ver |
| 26 dic 2025 | Grooten, Tommy 2217 | Grooten, Herman 2176 | 1-0 | A62 Defensa Benoni: Fianchetto Variation | Chessfestival Groningen 2025 | Open A | 44 | Ver |
| 26 dic 2025 | De Wit, Evan 2114 | Grooten, Herman 2176 | 0-1 | B51 Defensa Siciliana: Moscow Variation | Chessfestival Groningen 2025 Open A | 29 | Ver |