F2L 39
The algorithm, how to recognise it and how to practise it without cheating.
Recommended algorithm
R U2 R U R' U R U2 R29 moves · R and U only
Alternatives
R2 U2 F R' F' U2 R' U2 R'9 movesR U' R' U R U2 R2 F R F'10 movesF' U2 F' U2 R' F' R U2 F29 moves
How to recognise it
Both pieces are in the slot: the edge is solved, but the corner is twisted with white facing right.
Its inverse is another case
Do the 39 algorithm backwards, R2 U2 R' U' R U' R' U2 R', and you are solving 38.
That's why CubeDojo never scrambles 39 that way: it builds a random state with the case fixed, so you practise 39 and not 38.
Practise 39 now
Random-state scrambles, a timer and spaced review. Free, on the web and on your phone.