PLL Time Attack: Run All 21 PLL Algorithms in One Go

What is a PLL time attack?

On the SpeedSolving forum, cubers have been talking about this drill since 2007, in doubleyou's thread "21 PLL run" (SpeedSolving). The idea is simple: do all 21 PLL algorithms one after another in a single timed run.

There are no fixed rules. In the 2009 thread "PLL time attack discussion", members agreed on a few points (SpeedSolving):

• The order is up to you, as long as you do all 21 algorithms.
• You don't have to turn U before or after each algorithm.
• The cube doesn't have to end up solved. But lots of people like to pick an order that brings it back on its own, because then they know straight away whether they went wrong somewhere.

In the 2007 thread, a member called Joey said you shouldn't "cut" moves that cancel each other out between two algorithms, because then you aren't doing the whole algorithm. This post sticks to that: do every single move.

The picture below shows the T-perm, the best-known PLL algorithm. On the left is the case the T-perm solves, on the right is the cube after doing the T-perm:

Why practise PLL time attacks?

SpeedCubeShop advises CFOP solvers to practise the PLL step on its own many times with a timer, and to know all 21 algorithms well enough to do them without hesitating (SpeedCubeShop). A PLL time attack is one way to do that in just a few dozen seconds.

In our view, this drill helps in three ways:

• Finding your weak algorithms. In a run of 21 algorithms, any algorithm that makes you pause shows up straight away.
• Keeping your hands moving smoothly. You have to go from one algorithm to the next without stopping.
• Measuring progress with one number. The time for a whole run is easy to compare from one day to the next.

This drill does not train recognition: you already know which algorithm comes next. So it is only one part of a practice session, alongside full solves.

How to read the pictures

• Yellow face on top, green face in front. In the pictures, the right face is orange.
• Each picture has two cubes. On the left is the cube before the algorithm, on the right is the cube after it. Only the top layer is coloured in.
• Algorithms with M, x or y are drawn using an equivalent algorithm that only turns the outer faces, for that exact case.
• Notation: M is the middle slice, turned the same way as L; x and y turn the whole cube the same way as R and U. See more in Rubik's Cube notation for beginners.

One thing to know for later: many PLL algorithms undo themselves when you do them twice. Do the T-perm once on a solved cube and you get exactly the T-perm case shown on the left in the picture above. Do it once more and the cube is back where it started.

Mini version for beginners: the 6 algorithms of 2-look PLL

If you've only just got the hang of the 6 algorithms of 2-look PLL (T, Y, Ua, Ub, H, Z), start with this mini version. After each line the cube is back to solved, so you know straight away whether you got it right.

1. T-perm twice.
2. Y-perm twice.
3. H-perm twice.
4. Z-perm twice.
5. Ua-perm, then Ub-perm.

That makes 10 algorithms in total. We tried putting the four algorithms T, Y, H and Z together, each one once, in every possible order with U turns in between: none of them brought the cube back to where it started. That's why the mini version uses each algorithm twice.

T-perm twice

R U R' U' R' F R2 U' R' U' R U R' F'

The first time sets up the case in the left picture, and the second time brings the cube back as in the right picture:

Y-perm twice

F R U' R' U' R U R' F' R U R' U' R' F R F'

H-perm twice

M2 U M2 U2 M2 U M2

Z-perm twice

M2 U M2 U M' U2 M2 U2 M' U2

Ua-perm, then Ub-perm

R U' R U R U R U' R' U' R2

R2 U R U R' U' R' U' R' U R'

Ub is simply Ua read from the end back to the start, with every move turned the other way. The picture shows Ub: on the left is the cube after you do Ua, on the right is the cube after Ub.

The EasyRubic 21-algorithm order

We put this order together ourselves and checked it on the simulator. It has two parts:

• Part 1: four pairs of algorithms that are opposites of each other. After each pair, the cube is back where it started. These are four "checkpoints".
• Part 2: the other 13 algorithms. They only need two extra U turns in between, and after the last algorithm the cube is back where it started.

The whole run, read from left to right:

Ua - Ub - Aa - Ab - Ga - Gb - Gc - Gd - H - Z - E - T - F - Ja - Jb - Ra - U - Rb - U' - Y - V - Na - Nb

The 21 algorithms in this post add up to 285 moves (not counting x and y). Add the two U moves and you get 287 moves.

The picture below is the first checkpoint, the same as the Ua then Ub picture above: on the left is the cube after Ua, on the right is the cube after Ub.

Part 1: four pairs that bring the cube back

In each pair, the second algorithm does exactly the opposite of the first one. The picture for each pair shows the second algorithm: on the left is the cube after the first algorithm, on the right is the cube back where it started.

Pair 1: Ua, then Ub

R U' R U R U R U' R' U' R2

R2 U R U R' U' R' U' R' U R'

Pair 2: Aa, then Ab

x R' U R' D2 R U' R' D2 R2 x'

x R2 D2 R U R' D2 R U' R x'

Ab is also Aa read backwards, with every move turned the other way.

Pair 3: Ga, then Gb

R2 U R' U R' U' R U' R2 U' D R' U R D'

R' U' R U D' R2 U R' U R U' R U' R2 D

These two algorithms aren't move-by-move reverses of each other, but what they do to the cube is exactly opposite, so doing them back to back brings the cube back where it started.

Pair 4: Gc, then Gd

R2 U' R U' R U R' U R2 U D' R U' R' D

R U R' U' D R2 U' R U' R' U R' U R2 D'

Part 2: the other 13 algorithms

Each of these 13 algorithms undoes itself when you do it twice, but here you do each one only once. The order below needs exactly two U turns slipped in: U before Rb and U' before Y. Do it just like that, and after Nb the cube is back where it started.

The picture for each algorithm shows the case that algorithm solves, so you can get used to spotting it in a real solve. In the middle of a time attack run your cube will look different from the picture: that's normal.

H-perm

M2 U M2 U2 M2 U M2

Z-perm

M2 U M2 U M' U2 M2 U2 M' U2

E-perm

x' R U' R' D R U R' D' R U R' D R U' R' D' x

T-perm

R U R' U' R' F R2 U' R' U' R U R' F'

F-perm

R' U' F' R U R' U' R' F R2 U' R' U' R U R' U R

Ja-perm

R' U L' U2 R U' R' U2 R L

Jb-perm

R U R' F' R U R' U' R' F R2 U' R'

Ra-perm

R U' R' U' R U R D R' U' R D' R' U2 R'

Rb-perm (turn U first)

Turn the top face one U move, then do:

R2 F R U R U' R' F' R U2 R' U2 R

Y-perm (turn U' first)

Turn the top face one U' move, then do:

F R U' R' U' R U R' F' R U R' U' R' F R F'

V-perm

R' U R' U' y R' F' R2 U' R' U R' F R F

After the y move, you're holding the cube turned a quarter of the way round. Just keep holding it that new way for the last two algorithms.

Na-perm

R U R' U R U R' F' R U R' U' R' F R2 U' R' U2 R U' R'

Nb-perm

R' U R U' R' F' U' F R U R' F R' F' R U' R

This is the last algorithm. If everything went right, the cube is solved; it's just that, because of the y move in the V-perm, the face pointing towards you is now a colour other than green.

How to time a run and keep track of your results

1. Solve the cube, then hold it with the yellow face on top and the green face in front.
2. Start the EasyRubic 3x3 timer and do the whole run.
3. Stop the timer straight after the last algorithm. If the cube isn't back where it started, mark that run as failed and do it again more slowly to find where it went wrong.

The four checkpoints in Part 1 help you catch mistakes early: if the cube isn't back where it started after a pair, stop right there. There's no need to carry on.

The SpeedSolving forum has a few numbers to compare against, all reported by the cubers themselves, not competition results:

• doubleyou (2007) said one run took about 1 minute 15 to 1 minute 25 seconds.
• blah (2009) said their order could be done in under 40 seconds. They also suggested doing the hard algorithms first and the easy ones last, and setting a halfway target: if you're already slower than the target, start again from the beginning.

With the 287 moves of the order in this post, 40 seconds means more than 7 moves per second. Don't compare yourself with that number when you're just starting out. Compare yourself with how you did last week.

A PLL time attack is not a WCA competition event. It's just a drill to do at home.

Suggested practice plan

This is our own suggestion, not taken from any source:

• Just picked up 2-look PLL: do the mini version 3 times a day, before your full solves. No need to time it in the first week.
• Working towards full PLL: only put the algorithms you already know into the run. For an algorithm you don't know yet, do it twice in a row (if it undoes itself) or pair it with its opposite algorithm.
• Know all 21: 3 to 5 runs per session, and write down your best time. When one algorithm always makes you pause, practise it on its own for a few minutes, then do the whole run again.

For smoother, faster hands, see Rubik's Cube finger tricks.

Common mistakes

• Forgetting the two extra U turns. Without the U before Rb or the U' before Y, the cube won't come back to where it started at the end.
• Doing y the wrong way in the V-perm. y turns the whole cube the same way as U.
• Changing your grip after the V-perm. After the y move, keep holding the cube the new way for Na and Nb.
• Mixing up the G-perms in Part 1. The four G algorithms look quite alike. If pair 3 or pair 4 doesn't come back to where it started, check that you did the right G algorithm.
• Cutting moves between two algorithms. It makes the run faster, but then you're no longer practising the full algorithms.

Video

Want to see it in motion? The short video below from the Cube For Speed 2 channel on YouTube shows more of what this post covers. The video belongs to that channel and is embedded straight from YouTube.

Sources

• PLL time attack discussion (SpeedSolving.com forum)
• 21 PLL run (SpeedSolving.com forum)
• Getting Faster at CFOP with Our Tips and Tricks (SpeedCubeShop)
• PLL (SpeedSolving.com Wiki)