| Giraldilla Int. XD | 2018/11/23 11:20 | Mark Caljouw v Kai Schaefer | L | 2-0 |
| Giraldilla Int. XD | 2018/10/31 16:20 | Kai Schaefer v Mark Caljouw | L | 0-2 |
| Orleans Masters | 2019/03/20 08:40 | Kai Schaefer v Teck Zhi Soo | W | 2-0 |
| Orleans Masters | 2019/03/19 18:00 | Sam Parsons v Kai Schaefer | W | 0-2 |
| Swiss Open - Dublu Feminin - Calificari | 2019/03/12 11:00 | Kai Schaefer v Felix Burestedt | L | 1-2 |
| Spain Masters | 2019/02/20 15:20 | Pablo Abian v Kai Schaefer | L | 2-0 |
| Swiss Open - Dublu Feminin - Calificari | 2019/02/19 13:55 | Kim Bruun v Kai Schaefer | W | 1-2 |
| Swiss Open - Dublu Feminin - Calificari | 2019/02/19 11:00 | Kai Schaefer v Bernat Amaya | W | 2-0 |
| Giraldilla Int. XD | 2019/02/16 10:30 | Kai Schaefer v Vladimir Malkov | L | 1-2 |
| Giraldilla Int. XD | 2019/02/15 13:30 | Rajiv Ouseph v Kai Schaefer | W | 0-2 |
| Orleans Masters | 2019/03/20 20:00 | Giap Chin Goh v Mark Caljouw | W | 1-2 |
| Swiss Open | 2019/03/15 14:15 | Yuqi Shi v Mark Caljouw | L | 2-0 |
| Swiss Open | 2019/03/14 18:30 | Mark Caljouw v Parupalli Kashyap | W | 2-0 |
| Swiss Open | 2019/03/13 17:10 | Tommy Sugiarto v Mark Caljouw | W | 1-2 |
| German Open | 2019/02/27 20:25 | Mark Caljouw v Zii Jia Lee | L | 1-2 |
| Giraldilla Int. XD | 2019/02/23 17:00 | Mark Caljouw v Shifeng Li | W | 2-1 |
| Giraldilla Int. XD | 2019/02/23 10:20 | Mark Caljouw v Haichao Liu | W | 2-1 |
| Giraldilla Int. XD | 2019/02/16 13:30 | Viktor Axelsen v Mark Caljouw | L | 2-1 |