Learn · Level 3 · permutations · case 21 of 21
The Nb perm
Two corners across the diagonal trade places, and so do the left and right edges. 17 moves put every piece home.
The last layer is all yellow on top, and every piece of the first two layers is home. What remains is position: two corners across the diagonal trade places, and so do the left and right edges. This is the Nb permutation, one of the twenty-one ways an oriented last layer can still be shuffled.
No side of this one shows a bar or a matching pair: every face is a jumble, which is itself the giveaway.
On average one solve in seventy-two ends here. The algorithm runs 17 moves; play it slowly first, then step through it turn by turn with your own cube in hand.
Checked by simulation before publishing: the position shown plus the moves shown must produce a finished cube, and the algorithm must touch nothing outside its own job. The diagram and the player are drawn from the same simulated position, so they cannot disagree.