"Blurry subject, crisp background" challenge
I entered this challenge, accordingly to the challenge owner's rule which clearly mentioned "I want the subject to be out of focus". I was surprised that many of entrees are not disquilified even though their image of "blurry subject, crisp background" showing motion blur instead of out of focus blur.
Most likely, for an image to have motion blur will be using slow shutter speed and an aperture of 11 or more. Thus, the subject should be IN Focus, but just blurry because the object is moving and using slow shutter speed.