After painstakingly modding my Shengshou v4s a couple months ago (mod post coming soon), my interest in 4x4s has waxed and waned. On the one hand, I find it a welcome and more challenging distraction from 3x3s; on the other hand, those damn parity algorithms!?! I have finally committed them to muscle memory and am now trotting along at a 2:20 average using the Yau variation of the reduction method. (For more on Yau, and especially the cross-on-right variation that I find easier, check out Cyoubx’ really good Yau intro video.)

For months, parity was my albatross. I finally conquered it, so to speak, not only by finding and learning algorithms that worked for me, but also my learning about the root causes of parity. This was by far my deepest dive into puzzle theory and its associated patois. Keep reading past the jump for much more on the types of cube parity, what causes each, and, most importantly, what we really mean when we sloppily say that a cube has “parity.”

PARITY ALGORITHMS

If you’re just here for the algorithms, look no further:

OLL Parity [1] Rw U2 x Rw U2 Rw U2 Rw’ U2 Lw U2 Rw’ U2 Rw U2 Rw’ U2 Rw’ [2] (Rw Lw) U2 Lw’ U2 Rw’ U2′ x’ U2 Rw’ U2′ Rw U2 Rw’ U2′ Rw2 U2

PLL Parity Uw2 Rw2 U2 r2 U2 Rw2 Uw2

Here’s a (now muted due to copyright claims) video showing each:

Continue reading →