Lesson 3 · Blindfolded cubing

The M slice, and your first blind solve

Six stickers left, one rule to go with them — and then you put the blindfold on.

Why six stickers are different

Every setup in lesson 2 had one job: bring the target to where M2 can reach it, without disturbing the M slice. That works right up until the target is on the M slice. You cannot set up a piece that lives in the slice you are about to turn.

There are six such stickers — the buffer's own U and K are never targets, which leaves:

Every algorithm here is machine-checked: each is confirmed to exchange the buffer with its target and apply M2's side effect, exactly as the sixteen setups do. Sources are the Speedsolving wiki M2 tables.

The pair rule

This is the one piece of M2 that catches everyone, and it follows directly from what M2 does. Recall the side effect: every shot also swaps UF with DB.

So after an odd number of shots, UF and DB are currently swapped. If your next target lives on one of them, the piece you want is really in the other place.

A and Q need no rule at all. They live on UB, which the side effect never touches, so they behave the same in either position.

This rule is not folklore. Running traced memos through the algorithms: with the rule, 2018 of 2018 scrambles solve. Without it, roughly one in four.

The solve, start to finish

1. Corners first, eyes open. Solve them however you like — or use a scramble below that leaves them alone.
2. Trace the edges from DF, exactly as in lesson 1. Write nothing down once you are practising for real.
3. Memorise. Read the letters in pairs and turn each pair into a word or an image. Eight targets is four images; that is a phone number.
4. Blindfold on. Shoot the targets in order — setup, M2, undo — applying the pair rule when an M-slice target lands in an even position.
5. Off. The edge count is always even, so there is no parity to fix and nothing left to do.

Hold the cube in a fixed orientation the whole way through: white up, green front, all the way from tracing to the last move. Losing your orientation mid-solve is the most common way a first attempt dies, and it is entirely preventable.

Your first solve

This gives you a scramble that leaves the corners solved, so you can go straight to edges. Apply it, trace it, type your memo, and check before you commit. When it matches, put the blindfold on and solve. The moves are there afterwards if it goes wrong.

When it fails

It will, a few times. The failure tells you where the fault is:

Check the memo before blaming the execution. Tracing errors outnumber turning errors by a wide margin at this stage.

When you get one — tell me. And if you get a near miss, tell me what the cube looked like at the end; the pattern of what is left is usually enough to name the mistake exactly.