All events · 4x4x4 Cube · Practise · Algorithms
4x4 · Intermediate
Efficient centres and edge pairing, CFOP on the reduced cube, and fixing parity quickly. Consistent sub-90 solves.
Move sequences on this page are only checked to be legal moves for this puzzle in cubing.js. Treat them as demonstrations of the notation and the method, not as verified algorithm lists. Both parity algorithms above were additionally simulated: each leaves all centres unchanged and keeps every edge paired. Recognition advice follows from the way edges can be flipped and swapped, and is not machine-checked.
Faster centres
Solve two opposite centres first, then the four remaining centres in pairs. Use slice moves to insert a whole row of two pieces at a time instead of one piece per move.
Practise recognising when a centre is already fine and when the pieces you need are only one setup move away. Most time in the centre stage is lost looking, not turning.
Edge pairing in groups
Pair edges in groups. Build a few pairs, then join the next wings using the same slice move. Plan so that finished pairs stay out of the way of the slice you are about to use.
The last edges are the hardest because a careless move breaks pairs you already made. Leave yourself a clear way to finish: pair the second-to-last edge so that the last pair can be finished with a short sequence rather than a hunt.
Recognising parity before it costs you
Each parity case turns up in about half of solves, so you will meet them all the time. Learn to spot them as early as you can, so that you can fix them at the right moment instead of finding out at the very end.
Flipped-edge parity: at the last-layer orientation step, the top layer has an odd number of flipped edges (for example a single flipped edge). That cannot happen on a 3x3. Do the OLL parity algorithm, then solve the last layer normally.
Swapped-edge parity: after the last layer is oriented, two edges are swapped with nothing else wrong, or the permutation needs something no 3x3 PLL does. Do the PLL parity algorithm, then solve the last layer normally.
Rw U2 x Rw U2 Rw U2 Rw' U2 Lw U2 Rw' U2 Rw U2 Rw' U2 Rw' — OLL parity2R2 U2 2R2 Uw2 2R2 2U2 — PLL parityCFOP on the reduced cube
Once reduced, the cube is a 3x3 with the same rules. Use the 3x3 Intermediate guide from here: plan the cross, solve F2L by pairs and finish with two-look or full OLL and PLL. Handle any parity at the orientation and permutation steps as above.