ATP Kitzbuhel MD 07/19 17:00 26 Koolhof/Middelkoop v Daniel/Gimeno-Traver 6-3,6-2
French Open MD 05/24 17:25 24 Koolhof/Middelkoop v Lamasine/Olivetti 4-6,5-7
ATP Geneva MD 05/17 10:00 26 Koolhof/Middelkoop v Marach/Martin 6-4,2-6,10-8
Challenger Aix en Provence MD 05/03 13:10 26 Mektic/Sancic v Koolhof/Middelkoop 6-4,6-1
ATP Marrakech MD 04/04 15:50 26 Koolhof/Middelkoop v Ramos-Vinolas/Vesely 7-6,6-7,14-16
ATP Memphis Qual 02/13 03:35 27 Koolhof/Middelkoop v Johnson/Querrey 3-6,4-6
ATP Sofia MD 02/06 14:00 28 Koolhof/Middelkoop v De Bakker/Haase 2-6,7-6,11-9
ATP Sofia MD 02/02 18:00 26 Kuzmanov/Lazov v Koolhof/Middelkoop 7-6,3-6,10-12
Challenger Brest MD 10/25 13:45 29 Koolhof/Middelkoop v Skupski/Skupski 3-6,6-4,10-6
Challenger Brest MD 10/22 13:00 27 Koolhof/Middelkoop v Boltz/Jacq 6-0,6-3
Challenger Seville MD 09/10 16:35 28 Koolhof/Middelkoop v Cachin/Munar 7-6,6-3
Challenger Meerbusch MD 08/23 11:00 29 Koolhof/Middelkoop v Brown/Junaid 4-6,5-7
Challenger Meerbusch MD 08/20 12:00 27 Kretschmer/Satschko v Koolhof/Middelkoop 4-6,6-3,2-10
Challenger St Brieuc MD 04/09 17:35 27 Koolhof/Middelkoop v Cagnina/Gigounon 6-1,4-6,9-11
Challenger St Brieuc MD 04/08 15:00 26 Koolhof/Middelkoop v Cox/Willis Walkover
Challenger Guangzhou MD 03/11 05:55 26 Kretschmer/Satschko v Koolhof/Middelkoop 6-7,6-7
ITF France F3 MD 01/29 16:00 - Koolhof/Middelkoop v Authom/Mertens 6-3,6-4
Challenger Casablanca MD 01/14 15:05 27 Koolhof/Middelkoop v Mektic/Skugor 7-6,6-4