The wounded butterfly is an alteration of the standard butterfly trade by having one wing wider than the other. Compared to a butterfly, the wounded fly has a directional bias on the more narrow side.
Giving yourself a range by breaking the wing increases probability of a butterfly succeeding greatly. In Tom Sosnoff's earning trials by putting on wounded flies and standard butterflies, the broken wings outperformed by over 50%. .
Follow the slides below to see how the proper way to set up a wounded butterfly. And for everyone confused, we use wounded and broken wing interchangeably.