I also wondered the same and could not recognize any of the normal speed cubing methods.

There are algorithms that are more efficient than the typical speed cubing methods, but are based on large amounts of computation, rather than pattern matching, thus unfit for humans.

If it depends on large amounts of computation, how can it be considered more efficient? If it's precomputed, then it's again pattern matching. If by algorithm you mean the sequence of rotations, then yes there is a small upper bound that speedcubers typically exceed in solving any specific randomization. [I never liked that some call a fixed sequence of moves an algorithm.]

Rubik's Cube solution unlocked by memorising 3915 final move sequences[0].

> For the first time, a speedcuber has demonstrated a solution to the Rubik’s cube that combines the two final steps of the puzzle’s solution into one

[0] https://www.newscientist.com/article/2334632-rubiks-cube-sol...

> If it depends on large amounts of computation, how can it be considered more efficient?

More efficient in terms of rotations necessary to solve the cube.

I guess you mean efficient in that they produce a shorter (or even the shortest) sequence of moves to solve a given scramble. But if it takes 5 minutes of computation to produce the solve, then in practice they are not yet very efficient.

it depends how much you value a move, vs a computer instruction.

Get a faster computer and a larger cube, the trade-off is likely worth it. A rubik's cube isn't such an intractable problem, I doubt a computer can't solve it faster than a human: in the worst case, they can rely on the same algorithm. Then, they can try to find shortcuts or just shorter paths.

I always thought minimizing the number of moves was the goal, hence "more efficient" made sense to me too.

By computation in this case I mean evaluating the state of the cube after a series of moves. It’s extremely difficult for a human, but a computer can simulate millions of moves in a fraction of a second. So realistically, any modern computer can find a low rotation count solution to any scramble almost instantaneously.