put someone off their stroke

put (one) off (one's) stroke

To disturb, distract from, or interfere with what one is doing, such that they are unable to do it well. Having my parents watching while I worked on my painting really put me off my stroke. The boxer tried to put his opponent off his stroke by getting in his face right before the fight.
See also: off, put, stroke
Farlex Dictionary of Idioms.

put someone off their stroke

BRITISH
If something puts you off your stroke, it stops you from concentrating on what you are doing, so that you do not do it as well as usual. A sudden sound from behind me put me off my stroke and I missed the ball completely. Compare with put someone off their stride. Note: The reference here is to rowing, in which all the members of a team have to pull on their oars at exactly the same moment. Each pull of the oars is called a stroke.
See also: off, put, someone, stroke
Collins COBUILD Idioms Dictionary, 3rd ed.

put someone off their stroke

disconcert someone so that they do not work or perform as well as they might; break the pattern or rhythm of someone's work.
See also: off, put, someone, stroke
Farlex Partner Idioms Dictionary
See also:
  • put (one) off (one's) stroke
  • put one off one's stride
  • put one off stride
  • put somebody off their stride/stroke
  • put someone off their stride
  • put (one) off (one's) stride
  • drive (one) to distraction
  • drive someone to distraction
  • drive to distraction
  • not know what to do with yourself