Did he use a humboldt notch?if so it is basically just making the diaganol from the bottom instead of the conventional and making the back cut level with the undercut.I use it often and it works pretty good for me.
http://www.umext.maine.edu/onlinepub...es/2353.h2.gif
I nkow in that picture the back cut is slightly above the undercut but I don't do it that way and it works very well.Heres a picture of the conventional notch that most people use.
http://www.cdc.gov/nasd/docs/d000901...26/2353.h1.gif