Based on the work of Michel Zalewski, in his analysis of TCP/IP sequences.
“Take four numbers. Make X equal to the second number minus the first number. Make Y equal to the third number minus the second number. Then make Z equal to the last number minus the third number. Given the XYZ coordinate, draw a point. It turns out that many, many non-random datasets will have extraordinarily apparent regions in 3-space with increased density, reflecting common rates of change of the apparently random dataset. These regions are referred to as Strange Attractors, and can be used to predict future values from an otherwise random system.” – from the man page for “phentropy”.
Strange Attractors and TCP/IP Sequence Number Analysis » http://razor.bindview.com/publish/papers/tcpseq.html