play into someone's hands
US /pleɪ ˈɪntu ˈsʌmwʌnz hændz/
UK /pleɪ ˈɪntu ˈsʌmwʌnz hændz/

1.
iemand in de kaart spelen
to do exactly what your opponent wants you to do, so that they gain an advantage over you
:
•
By arguing with him, you're just playing into his hands.
Door met hem te discussiëren, speel je hem alleen maar in de kaart.
•
The opposition's mistakes played right into the government's hands.
De fouten van de oppositie speelden de regering recht in de kaart.