| Jul 24, 2026 | Habig | 0–1 | Den Hartog | Round 4: Habig, Bryan - Den Hartog, Marijn | English Opening: King's English Variation, Kramnik-Shirov Counterattack | |
| Jul 23, 2026 | Den Hartog | 0–1 | Harshavardhan G B | Round 3: Den Hartog, Marijn - Harshavardhan G B | Ruy Lopez: Morphy Defense, Anderssen Variation | |
| Jul 22, 2026 | Lu | 0–1 | Den Hartog | Round 2: Lu, Yunong Elias - Den Hartog, Marijn | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack, Fianchetto Variation | |
| Jul 21, 2026 | Den Hartog | 0–1 | Peyrer | Round 1: Den Hartog, Marijn - Peyrer, Konstantin | King's Indian Attack: Symmetrical Defense | |
| Jul 19, 2026 | Schoorl | ½–½ | Den Hartog | Amsterdam Chess Festival 2026 - Groep A | English Opening: Symmetrical Variation, Three Knights, Fianchetto Variation | |
| Jul 18, 2026 | Den Hartog | 1–0 | Dovgaliuk | Amsterdam Chess Festival 2026 - Groep A | Catalan Opening: Open Defense, Classical Line | |
| Jul 17, 2026 | Den Hartog | 1–0 | Brienen | Amsterdam Chess Festival 2026 - Groep A | Indian Defense: Knights Variation | |
| Jul 15, 2026 | De Boer | 1–0 | Den Hartog | Amsterdam Chess Festival 2026 - Groep A | Italian Game: Classical Variation, Giuoco Pianissimo | |
| Jul 14, 2026 | Den Hartog | 1–0 | Bosboom | Amsterdam Chess Festival 2026 - Groep A | Queen's Pawn Game: Modern Defense | |
| Jul 12, 2026 | Den Hartog | 1–0 | Andringa | Amsterdam Chess Festival 2026 - Groep A | English Opening: Neo-Catalan | |
| Jul 10, 2026 | Albers | ½–½ | Den Hartog | Amsterdam Chess Festival 2026 - Groep A | English Opening | |
| May 24, 2026 | Simenon | 1–0 | Den Hartog | Round 13: Simenon, Jozef - Den Hartog, Marijn | Polish Opening | |
| May 24, 2026 | Den Hartog | 0–1 | Kamphuis | Round 12: Den Hartog, Marijn - Kamphuis, Jasper | Vienna Game: Mieses Variation | |
| May 24, 2026 | Terlouw | 1–0 | Den Hartog | Round 11: Terlouw, Wouter - Den Hartog, Marijn | Queen's Gambit Declined: Janowski Variation | |
| May 24, 2026 | Den Hartog | 0–1 | Van der Werf | Round 10: Den Hartog, Marijn - Van der Werf, Mark | Mieses Opening | |
| May 24, 2026 | Den Hartog | 0–1 | Ootes | Round 8: Den Hartog, Marijn - Ootes, Lars | Pirc Defense | |
| May 24, 2026 | Slagboom | 0–1 | Den Hartog | Round 9: Slagboom, Leandro - Den Hartog, Marijn | French Defense: Rubinstein Variation, Kasparov Attack | |
| May 23, 2026 | Grooten | 0–1 | Den Hartog | Round 5: Grooten, Tommy - Den Hartog, Marijn | Queen's Gambit Declined: Janowski Variation | |
| May 23, 2026 | De Boer | 0–1 | Den Hartog | Round 7: De Boer, Eelke - Den Hartog, Marijn | French Defense: Advance Variation, Euwe Variation | |
| May 23, 2026 | Den Hartog | 1–0 | Jellema | Round 6: Den Hartog, Marijn - Jellema, Pieter | Caro-Kann Defense: Endgame Variation | |
| May 23, 2026 | Aravindhan | ½–½ | Den Hartog | Round 4: Aravindhan, Achyuth - Den Hartog, Marijn | Caro-Kann Defense | |
| May 23, 2026 | Den Hartog | 0–1 | Grochal | Round 3: Den Hartog, Marijn - Grochal, Joey | Van Geet Opening | |
| May 23, 2026 | Bekker | ½–½ | Den Hartog | Round 2: Bekker, Stefan - Den Hartog, Marijn | English Opening: Agincourt Defense, Bogoljubow Defense | |
| May 23, 2026 | Den Hartog | 1–0 | Pel | Round 1: Den Hartog, Marijn - Pel, Bonno | Zukertort Opening: Kingside Fianchetto | |
| Jun 6, 2025 | Den Hartog | 0–1 | Dann | Round 1: Den Hartog, Marijn - Dann, Matthias | Sicilian Defense: Keres Variation | |
| Apr 18, 2025 | Roshka | 1–0 | Den Hartog | Round 2: Roshka, Yevgeniy - Den Hartog, Marijn | Bogo-Indian Defense: Retreat Variation | |