Daily F2L Discussion - Case 9

Case 9

Setup: R' U R U R' U R U' y

Most important solution: y' U R' U' R U' R' U' R

Angles: Easy from FL + BR. Harder from FR + BL.

Mirror: Case 10

Discussion of Case 9:

This case is best handled from the FL and BR using very intuitive algorithms. Since the two top stickers have different (and non-cross) colors, this case is solved by reduction to case 3. Note that the line of action, as mentioned in case 3, is pointing to the incorrect edge. An important point is that in this case, you can hide either the edge or the corner and reposition the other piece.

Let's use y' U R' U' R U' R' U' R as an example. y' is used to move the empty slot to the BR. U R' is used to hide the corner. The edge is repositioned with U', and the corner is unhidden with R. We now have case 3, which can be solved with U' R' U' R.

Alternatively, you can use y' U2 R' U R U R' U' R. Once again, y' is used to move the empty slot from the FR to the BR. U2 R' is used to hide the edge. U repositions the corner, and R unhides the edge. Once again, we are left with case 3, which is solved with U R' U' R.

From the FR, you can use a less intuitive algorithm (F R U R' U' F' R U' R') to avoid a cube rotation. It's a fairly trivial algorithm to learn, though, as the first 6 moves make up a T-OLL case that you likely already know. The application of this sub-algorithm reduces this case to case 1, which then then be solved with a R U' R'.

Algorithms

[Front Right (FR)](http://cube.crider.co.uk/visualcube.php?fmt=png&size=200&stage=f2l&case=U' R U' R' U F' U' F.png)

F R U R' U' F' R U' R'

y' + {BR}

y + {FL}

U r U R' U' r' R2 U' R'

[Back Left (BL)](http://cube.crider.co.uk/visualcube.php?fmt=png&size=200&stage=f2l&case=y2U' R U' R' U F' U' F.png)

y + {BR}

y' + {FL}

U l U L' U' l' L2 U' L'

[Front Left (FL)](http://cube.crider.co.uk/visualcube.php?fmt=png&size=200&stage=f2l&case=y'U' R U' R' U F' U' F.png)

U L' U' L U' L' U' L

U2 L' U L U L' U' L

[Back right (BR)](http://cube.crider.co.uk/visualcube.php?fmt=png&size=200&stage=f2l&case=yU' R U' R' U F' U' F.png)

U R' U' R U' R' U' R

U2 R' U R U R' U' R

Please feel free to add the discussion by posting your personal tips, tricks, or algorithms that have not been documented. If you spot an error, please let me know ASAP so it can be corrected for the benefit of the subreddit.

Contributors

calesch

Previous Daily F2L Discussions

1 2 3 [4] (https://www.reddit.com/r/Cubers/comments/42esto/daily_f2l_discussion_case_4/) 5 6 [7] (https://www.reddit.com/r/Cubers/comments/43fpd6/daily_f2l_discussion_case_7/) 8 9