K4 mixes reduction, blockbuilding, edge pairing and direct solving techniques to produce a method that can quickly and efficiently solve a 4x4x4 (Revenge) cube.
It should be noted that while K4 is designed specifically for the 4x4x4 cube, it can be applied to any size of cube. Modifications can be made to make it friendlier to solve on the bigger (>=5x5x5) cubes.
If you have a good understanding of commutators, the algorithms used in this method will come naturally to you - you will likely not have to learn the majority of them. If you do not, your understanding will hopefully improve when you realise how closely each algorithm in a step is related to the others. It is highly recommended to learn how these work elsewhere or at least grasp the basic concepts before delving too deep into this site.
However, it's not a completely free ride - there are parity algs, 4-cycles and other special cases you have to simply learn like any other algorithm if you want to get fast. All the algorithms are written in WCA notation.
If you're reading this I assume you already know how to solve the 4x4x4 and want to learn this for whatever reason. Because of this, I will not waste too much time explaining how to make a white centre, for example.
While I have tried to make a note of all the shortcuts and tricks I use, I will have invariably missed some. Feel free to inform me of these and anything else you discover.
K4 stands for Kirjava's 4x4x4 Method.
You can find me as 'Kirjava' on #rubik at irc.freenode.net or on speedsolving.com.
Thom Barlow (snkenjoiatgmaildotcom)