Lesson 2 · Blindfolded cubing
Turning a letter into a turn. One idea — setup, M2, undo — covers sixteen of the
twenty-two targets, and it is the same shot you will use for wings on the 4x4.
The goal now is a blindfolded solve of the edges alone: solve the corners with your eyes open, look once, put the blindfold on, and finish. It is a real blindfolded solve, it is reachable in days rather than weeks, and everything in it carries forward unchanged.
And it comes with a gift. If the corners are already solved, the edge permutation must be even — that is a law of the cube, not a coincidence. An even permutation means an even number of targets, and an even number of targets means parity can never happen. The single fiddliest part of blind solving is simply absent.
Hold the cube normally. M2 exchanges the DF edge with the
UB edge. That is your shot: DF is the buffer, so M2 on its own is a
shot to A.
It also does something else, and the method is built around it:
M2 swaps UF with DB as well, and turns the U/D and F/B centres.
That extra half undoes itself on the next M2. So shots come in pairs, and after an
even number of them the cube is clean. It is the reason M2 needs an even target count — and the
reason your edges-only solve, which is always even, never needs a parity fix.
M2 only ever hits UB. For any other target the recipe is three steps:
M2.
Take J, the F sticker of FR. Bring FR up with U, so the sticker you
want lands at UB after R: the setup is U R U'. Then
M2. Then U R' U' to put it back. The whole shot:
U R U' M2 U R' U'
The undo is the setup reversed, with every turn's direction flipped. You never memorise it separately — if you can do the setup, you can undo it.
The setup must not disturb the M slice, or it would wreck the shot itself. That is why every setup below is built from ordinary face turns — U, B, R and L — and never from M.
Do not learn sixteen strings. Learn four shapes and which face each target lives on — the sheet then reads itself.
Notice the symmetry: the top two groups carry the target up to UB with U, the bottom two carry it round the back with B. Same two shapes, one for each face the target lives on. Nothing rotates, so the cube stays in one orientation from the first move to the last.
Cube in hand for these. Type the setup only — not the M2, not the undo.
Any correct setup is accepted, not just the one on the sheet. The drill applies what you type,
does M2, reverses it, and checks the result against what a shot to that target must
do. If you find your own way there, it will say so.
Six stickers sit on the M slice itself — A, Q,
C, I, W, S — and cannot be
set up, because the setup would move the slice they live on. A is free: it is
plain M2. The rest is lesson 3, together with your first full edges-only solve.
Between now and then: the sixteen above are 76% of all targets, and with A that is more than eight in ten. Drill the shapes until your hands do them without the sheet — the M2 setup trainer exists for exactly that, and it aims its scrambles at whichever setups you are worst at.
Primary source
Speedsolving wiki — M2/R2.
The canonical target table, and the same page that confirms r2 on the 4x4 is M2 with the slice
swapped: most r2 algorithms are these algorithms with M2 replaced by
r2. Everything you drill today you will reuse on the 4x4.
If a setup will not come, tell me which target and we will find a shape that suits your hands — there is more than one right answer for most of them, and the drill will accept yours.