20140629

Speedsolving Post: "Shortest" PLL Algs?

From an October 2013 discussion at http://www.speedsolving.com/forum/showthread.php?44398:

What are the shortest possible PLL algs, in terms of how long they are when written down? This should be more interesting than just finding move-optimal stuff, and I think there's a lot of room for creativity. The most common algs may not be the shortest!

To start with, the following notations are OK:
- [P,Q] is a commutator (that is, P Q P' Q')
- [P:Q] is a setup move/conjugate (that is, P Q P')
- (P)n is P repeated n times; parentheses are unnecessary if it's clear what P is
- Any face or slice moves, rotations, or lowercase moves.
Also, the algorithm can do the PLL on any face, and you do not have to include any adjustment at the end, or rotations at the very start/end.






And the shortest algs we found:


A: L'[F,R'B2R]L, L'[R'd2R,U]L (thanks to Stefan Pochmann)
E: [[RU'L:D2],U2] (thanks to TDM)
F: R'URU'R2F'U'FU[R,F]R2
G: [RL:U2][F'UB':d2], [R'UL',d2][BF:U2], L'R'U2LR[FU'B,d2], [LU'R,d2]B'F'U2BF
H: (M2U)6
J: [[RU'L:d2],U], [[R'UL':d2],U]
N: (r'DrU2)5, (rDr'U2)5
R: R[U2R'U2,UR'F'R]R', R'[U2RU2,U'RBR']R
T: [R2D':F2][B2D:L2]
U: M2uMu2MuM2, B2UMU2M'UB2
V: [F'UBU'F:U][U2,B]
Y: F2[DR2:U][R'U'R:F2]
Z: (UF2)6M'U2M (thanks to Moritz Karl)

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