| Intern 2024/2025 |
| Group 1 - Piet Kooiman |
| Site | Dijckzigt | Start date | 9-9-2025 |
| City | Utrecht | End date | 1-7-2026 |
| Country | Netherlands | Pairing system | Ladder |
| Organization | Schaakvereniging Oud Zuylen Utrecht | Arbiters | Marc Jongerius |
| Piet Kooiman | |
| ID | |
| Rating | 1843 |
| Categories | |
| Nr. | White | Black | Result |
| 1 | Jan Maarten van den Boogaart | Piet Kooiman | 1−0 |
| 2 | Piet Kooiman | Wout van Veen | 0−1 |
| 3 | Marc Jongerius | Piet Kooiman | ½−½ |
| 4 | Paul van der Pas | Piet Kooiman | 1−0 |
| 5 | Piet Kooiman | Marc Speijers | 1−0 |
| 6 | Piet Kooiman | Rene ten Bos | 1−0 |
| 7 | Maarten Post | Piet Kooiman | ½−½ |
| 8 | Piet Kooiman | Abs with msg | |
| 9 | Piet Kooiman | Abs with msg | |
| 10 | Piet Kooiman | Abs with msg | |
| 11 | Piet Kooiman | Abs with msg | |
| 12 | Piet Kooiman | Marc Jongerius | 1−0 |
| 13 | Piet Kooiman | Abs with msg | |
| 14 | Piet Kooiman | Abs with msg | |
| 15 | Piet Kooiman | Abs with msg | |
| 16 | Piet Kooiman | Abs with msg | |
| 17 | Wout van Veen | Piet Kooiman | 0−1 |
| 18 | Piet Kooiman | Harm−Theo Wagenaar | 0−1 |
| 19 | Piet Kooiman | Abs with msg | |
| 20 | Piet Kooiman | Abs with msg | |
| 21 | Piet Kooiman | Jordy Lahr | 1−0 |
| 22 | Piet Kooiman | Wout van Goor | ½−½ |
| 23 | Jaap van der Tuuk | Piet Kooiman | ½−½ |
| 24 | Piet Kooiman | Jan Maarten van den Boogaart | 1−0 |
| 25 | Geert Verweij | Piet Kooiman | 0−1 |