F2L 41
The algorithm, how to recognise it and how to practise it without cheating.
Recommended algorithm
R U F R U R' U' F' R'9 moves
Alternatives
F' R' U' F' U F R U F9 movesR U' R' U2 R U R' F' U' F10 movesR U' R' U2 F' U' F2 R' F' R10 moves
How to recognise it
Both pieces are in the slot, with the edge flipped and the corner twisted so white faces right.
Its inverse is another case
Do the 41 algorithm backwards, R F U R U' R' F' U' R', and you are solving 40.
That's why CubeDojo never scrambles 41 that way: it builds a random state with the case fixed, so you practise 41 and not 40.
Practise 41 now
Random-state scrambles, a timer and spaced review. Free, on the web and on your phone.