could (do something) with one hand tied behind (one's) back

could (do something) with one hand tied behind (one's) back

Could do something with very little or no difficulty, or complete or accomplish something in a relaxed, carefree, or effortless manner. I'm a professional musician, so that song is hardly a challenge—I could play it with one hand tied behind my back!See also: back, behind, could, hand, one, tie