According to Aaron Pynenberg, Krumphau is a normal long edge cut to the sword until the last moment when it is turned over. He writes,

My thought is that I am “cutting” with the long edge initially, and the long edge makes contact first, but then as my hands cross then the short edge actually forces the other sword down after it makes contact, that last video showed the “best” possible outcome as there are times when you can do this without even having to make contact here is a video showing what happens most often

See his video here: http://vimeo.com/49951783

This appears to work much better than my Krumphau, which begins as a short edge cut. It also gives you more flexibility, as this late decision point also gives you the option to turn it into a Schielhauw.