| May 2, 2026 | Leenhouts | 1–0 | Van Batenburg | Round 9: Leenhouts, Koen - Van Batenburg, Mees | Nimzo-Indian Defense: Kmoch Variation | |
| May 2, 2026 | Grochal | ½–½ | Leenhouts | Round 8: Grochal, Joey - Leenhouts, Koen | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| May 2, 2026 | Leenhouts | 1–0 | Ferreira | Round 7: Leenhouts, Koen - Ferreira, Jorge Viterbo | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| May 2, 2026 | Leenhouts | 1–0 | Bhattacharjee | Round 6: Leenhouts, Koen - Bhattacharjee, Sourav | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| May 2, 2026 | Zatonskih | 1–0 | Leenhouts | Round 5: Zatonskih, Anna - Leenhouts, Koen | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| May 2, 2026 | Leenhouts | 1–0 | Grooten | Round 4: Leenhouts, Koen - Grooten, Herman | Nimzo-Indian Defense: Kmoch Variation | |
| May 2, 2026 | Den Heijer | 0–1 | Leenhouts | Round 3: Den Heijer, Rolinde - Leenhouts, Koen | Sicilian Defense: Kan Variation, Wing Attack | |
| May 2, 2026 | Leenhouts | 1–0 | De Dreu | Round 2: Leenhouts, Koen - De Dreu, Dies | Semi-Slav Defense: Main Line | |
| May 2, 2026 | Moeri | 0–1 | Leenhouts | Round 1: Moeri, Erick - Leenhouts, Koen | Sicilian Defense: Kan Variation, Wing Attack | |
| Feb 7, 2026 | Dambacher | 0–1 | Leenhouts | Round 7: Dambacher, Martijn - Leenhouts, Koen | Queen's Gambit Declined: Traditional Variation | |
| Dec 12, 2025 | Leenhouts | ½–½ | De Vreugt | 2. Bundesliga in Mülheim | Nimzo-Indian Defense: Kmoch Variation | |
| Dec 6, 2025 | Vrolijk | ½–½ | Leenhouts | 2. Bundesliga in Mülheim | English Opening: Agincourt Defense | |
| Oct 4, 2025 | Leenhouts | 1–0 | Lopez | Round 2: Leenhouts, Koen - Lopez, Jasel | English Defense | |
| Jul 30, 2025 | Leenhouts | 1–0 | Wink | Round 9: Leenhouts, Koen - Wink, Luka | Nimzo-Indian Defense: Normal Variation, Botvinnik System | |
| Jul 29, 2025 | Albers | 1–0 | Leenhouts | Round 8: Albers, Sasa - Leenhouts, Koen | Sicilian Defense: Najdorf Variation, Zagreb Variation | |
| Jul 28, 2025 | Leenhouts | 0–1 | Maatman | Round 7: Leenhouts, Koen - Maatman, Nick | Nimzo-Indian Defense: Normal Variation, Classical Defense | |
| Jul 27, 2025 | Labruyere | 0–1 | Leenhouts | Round 6: Labruyere, Roger - Leenhouts, Koen | Sicilian Defense: Najdorf Variation, English Attack | |
| Jul 26, 2025 | Leenhouts | ½–½ | Korneev | Round 5: Leenhouts, Koen - Korneev, Oleg | Semi-Slav Defense: Meran Variation, Lundin Variation | |
| Jul 25, 2025 | Nemegeer | ½–½ | Leenhouts | Round 4: Nemegeer, Arne - Leenhouts, Koen | Sicilian Defense: Moscow Variation | |
| Jul 23, 2025 | Vandenhole | 0–1 | Leenhouts | Round 2: Vandenhole, Kobe - Leenhouts, Koen | Sicilian Defense: Moscow Variation | |
| Jul 22, 2025 | Leenhouts | 1–0 | Reuter | Round 1: Leenhouts, Koen - Reuter, Julian-Frank | Semi-Slav Defense: Chigorin Defense | |
| Jul 16, 2025 | Leenhouts | ½–½ | Schuricht | Round 3: Leenhouts, Koen - Schuricht, Emil Frederick | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Apr 5, 2025 | Ten Hertog | ½–½ | Leenhouts | KNSB Meesterklasse 2024-2025 | Hungarian Opening | |
| Mar 8, 2025 | Leenhouts | 1–0 | Van de Oudeweetering | KNSB Meesterklasse 2024-2025 | Semi-Slav Defense: Meran Variation, Lundin Variation | |
| Feb 8, 2025 | De Winter | ½–½ | Leenhouts | KNSB Meesterklasse 2024-2025 | Sicilian Defense: Kan Variation | |
| Nov 23, 2024 | Maatman | ½–½ | Leenhouts | KNSB Competitie, ronde 4 | English Opening: Symmetrical Variation, Three Knights Variation | |
| Oct 25, 2024 | Haring | 1–0 | Leenhouts | 39th European Chess Club Cup | Scandinavian Defense: Main Line, Mieses Variation | |
| Oct 24, 2024 | Leenhouts | 1–0 | Chukavin | 39th European Chess Club Cup | Nimzo-Indian Defense: Sämisch Variation | |
| Oct 22, 2024 | Leenhouts | 1–0 | Schreiner | 39th European Chess Club Cup | Slav Defense | |
| Oct 21, 2024 | Gorshtein | ½–½ | Leenhouts | 39th European Chess Club Cup | Tarrasch Defense: Dubov Tarrasch | |
| Oct 20, 2024 | Leenhouts | 1–0 | Ortega Ruiz | 39th European Chess Club Cup | Benoni Defense: Four Pawns Attack, Main Line | |
| Sep 21, 2024 | Beukema | 1–0 | Leenhouts | KNSB Meesterklasse 2024-2025 | Sicilian Defense: Closed, Korchnoi Defense | |
| Jul 27, 2024 | Grooten | 0–1 | Leenhouts | Round 5: Grooten, Herman - Leenhouts, Koen | Queen's Gambit Declined: Vienna Variation, Quiet Variation | |
| Jul 26, 2024 | Leenhouts | ½–½ | Beerdsen | Round 4: Leenhouts, Koen - Beerdsen, Thomas | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Jul 25, 2024 | Slagboom | ½–½ | Leenhouts | Round 3: Slagboom, Leandro - Leenhouts, Koen | Nimzo-Indian Defense: Rubinstein System, Rubinstein Variation | |
| Jul 24, 2024 | Leenhouts | 1–0 | Vos | Round 2: Leenhouts, Koen - Vos, Tjark | Grünfeld Defense: Exchange Variation | |
| Jul 23, 2024 | Dordevic | 0–1 | Leenhouts | Round 1: Dordevic, Tom - Leenhouts, Koen | Queen's Pawn Game: Symmetrical Variation | |
| Jul 22, 2024 | Leenhouts | 0–1 | De Winter | Round 6: Leenhouts, Koen - De Winter, Arthur | Queen's Gambit Accepted: Classical Defense, Alekhine System | |
| Dec 14, 2024 | Gallasch | 0–1 | Leenhouts | Round 5: Gallasch, Jonas - Leenhouts, Koen | Queen's Gambit Accepted: Normal Variation, Traditional System | |
| Nov 9, 2024 | Leenhouts | 1–0 | Willemze | Round 3: Leenhouts, Koen - Willemze, Thomas | Queen's Gambit Declined | |
| Oct 23, 2024 | Pechac | 1–0 | Leenhouts | Round 4: Pechac, Jergus - Leenhouts, Koen | Sicilian Defense: Kan Variation | |
| Aug 10, 2024 | Leenhouts | 1–0 | Goossens | Round 9: Leenhouts, Koen - Goossens, Hanne | King's Indian Attack | |
| Aug 9, 2024 | Perestjuk | 0–1 | Leenhouts | Round 8: Perestjuk, Marko - Leenhouts, Koen | Sicilian Defense: Kan Variation, Polugaevsky Variation | |
| Aug 8, 2024 | Leenhouts | 0–1 | Setyaki | Round 7: Leenhouts, Koen - Setyaki, Azarya Jodi | Slav Defense: Quiet Variation, Schallopp Defense | |
| Aug 7, 2024 | Fernandez | ½–½ | Leenhouts | Round 6: Fernandez, Daniel Howard - Leenhouts, Koen | Sicilian Defense: French Variation | |
| Aug 6, 2024 | Leenhouts | 1–0 | Den Heijer | Round 5: Leenhouts, Koen - Den Heijer, Rolinde | Sicilian Defense: Chekhover Variation | |
| Aug 5, 2024 | Nieuwelink | 0–1 | Leenhouts | Round 4: Nieuwelink, Kees - Leenhouts, Koen | French Defense: Knight Variation | |
| Aug 4, 2024 | Romkes | ½–½ | Leenhouts | Round 2: Romkes, Abel - Leenhouts, Koen | Nimzo-Indian Defense: Classical Variation, Berlin Variation, Pirc Variation | |
| Aug 3, 2024 | Leenhouts | 1–0 | Schreidl | Round 1: Leenhouts, Koen - Schreidl, Michael | Catalan Opening: Open Defense, Classical Line | |
| Aug 1, 2024 | Leenhouts | 1–0 | Baselmans | Round 9: Leenhouts, Koen - Baselmans, Luuk | Nimzo-Indian Defense: Kmoch Variation | |
| Jul 31, 2024 | Buckels | 1–0 | Leenhouts | Round 8: Buckels, Valentin - Leenhouts, Koen | Queen's Pawn Game: London System | |
| Jul 30, 2024 | Leenhouts | 1–0 | Labruyere | Round 7: Leenhouts, Koen - Labruyere, Roger | Zukertort Opening: Queen's Gambit Invitation | |
| May 29, 2023 | Leenhouts | ½–½ | Van der Hagen | Limburg Open | King's Indian Defense: Sämisch Variation, Panno Main Line | |
| May 28, 2023 | Leenhouts | 1–0 | De Boer | Limburg Open | Nimzo-Indian Defense: Normal Variation | |
| May 28, 2023 | Elgersma | * | Leenhouts | Limburg Open | ? | |
| May 28, 2023 | Schoorl | ½–½ | Leenhouts | Limburg Open | Zukertort Opening: Reversed Grünfeld | |
| Aug 29, 2021 | Leenhouts | ½–½ | Domingo Nunez | Guimaraes Chess 2021 | Benoni Defense: Fianchetto Variation | |
| Aug 29, 2021 | Krause | 0–1 | Leenhouts | Guimaraes Chess 2021 | Semi-Slav Defense: Normal Variation | |
| Aug 28, 2021 | Leenhouts | 1–0 | Lucas | Guimaraes Chess 2021 | King's Indian Defense: Orthodox Variation, Gligoric-Taimanov System | |
| Aug 28, 2021 | Grigoryan | 1–0 | Leenhouts | Guimaraes Chess 2021 | Queen's Pawn Game: Accelerated London System | |
| Aug 27, 2021 | Jimenez Martinez | 0–1 | Leenhouts | Guimaraes Chess 2021 | King's Indian Defense: Sämisch Variation, Sämisch Gambit | |
| — | Leenhouts | 1–0 | Groen | HZ University of Applied Sciences Chess Tournament | Tarrasch Defense: Classical Variation | |
| — | Leenhouts | ½–½ | Wunnink | HZ University of Applied Sciences Chess Tournament | Nimzo-Indian Defense: Normal Variation, Botvinnik System | |
| — | Leenhouts | 1–0 | Weller | HZ University of Applied Sciences Chess Tournament | Nimzo-Indian Defense: Sämisch Variation, Keres Variation | |
| — | Leenhouts | 1–0 | Van der Werf | HZ University of Applied Sciences Chess Tournament | Trompowsky Attack | |
| — | Czappa | 0–1 | Leenhouts | HZ University of Applied Sciences Chess Tournament | Queen's Pawn Game: London System | |
| — | Ronge | ½–½ | Leenhouts | HZ University of Applied Sciences Chess Tournament | Zukertort Opening: Reversed Grünfeld | |
| — | Stange | 0–1 | Leenhouts | HZ University of Applied Sciences Chess Tournament | Grünfeld Defense: Brinckmann Attack, Grünfeld Gambit, Botvinnik Variation | |
| — | Eljanov | 1–0 | Leenhouts | HZ University of Applied Sciences Chess Tournament | Sicilian Defense: Kan Variation | |
| — | Van Delft | 0–1 | Leenhouts | HZ University of Applied Sciences Chess Tournament | Sicilian Defense: Kan Variation, Polugaevsky Variation | |