Stadium: Grandstand Round: 26 Ground: Hardcourt outdoor
| ATP - Montpellier - Doubles Hommes | 2018/02/08 13:45 | Koolhof W / Sitak A v Arends S / Sancic A | 6-3,4-6,5-10 |
| ATP - Montpellier - Doubles Hommes | 2018/02/07 19:25 | Dodig I / Ram R v Koolhof W / Sitak A | 6-2,5-7,0-10 |
| Newport Beach, USA, Doubles | 2018/01/24 23:50 | Koolhof W / Sitak A v Huey T / Kudla D | 2-6,1-6 |
| Open d'Australie - Doubles Hommes | 2018/01/19 01:30 | Koolhof W / Sitak A v Marach O / Pavic M | 7-6,4-6,4-6 |
| Open d'Australie - Doubles Hommes | 2018/01/17 01:40 | Gojowczyk P / Mayer F v Koolhof W / Sitak A | 2-6,1-6 |
| ATP - Auckland - Doubles Hommes | 2018/01/09 08:30 | Koolhof W / Sitak A v Klaasen R / Venus M | 1-6,7-6,7-10 |
| Brisbane, Australie, Doubles | 2018/01/06 01:30 | Koolhof W / Sitak A v Mayer L / Zeballos H | 6-4,1-6,6-10 |
| Brisbane, Australie, Doubles | 2018/01/03 03:10 | Koolhof W / Sitak A v Johnson/Muller | 7-6,7-5 |