New FMC-ER at BW Open 2013

And here his solution: kind of lucky but not really undeserved, too.
Scramble: F' U2 L' D L F' L' B D2 B2 R F2 L' B2 R' L2 D2 R' U2

Start on Normal:
Double X-Cross: R2 U' B D2 B' D' L' B D'
Switch to inverse:
F2L-1: F R F' D' R2 D
Finish/LL-Skip: R' U' B U' B' U2

Solution: R2 U' B D2 B' D' L' B D' U2 B U B' U R D' R2 D F R' F' - 21 Moves
 
Nice scramble!

Clearly some effort was put into it (not staying with the 2x2x2 and the switch)

here's what I got straight of the 2x2x3 on the normal scramble:
R D' R2 D - F2L-1
F' U F U' - edge play
R2 U' R' U R2 - leaves 3 corners in 22 moves
too lazy for insertions :)
 
I thought the solution were not supposed to have anything to do with the scramble?

It doesn't. The scramble is just a "black box", it does a permutation on the cubies. But every permutation has a direct inverse (see the so called "cube group" in group theory), and you can clearly build up a solution for the inverse just as well.

With other words: if I change the given scramle to another one, which contains 200 moves, but does the same on the cube, it would not effected the solution and the way it has been found.

EDIT: for example, let's say in the competition they give just the scrabled cube - but not the scrabling itself. You search for a longer solution (for example, naive CFOP with 50-60 moves), write it down, and use it as your new scrambling algorithm. Of course you can still use its inverse. And again, the winner would came up with the same solution as above, with 21 moves. And the original scrabling would not even known - but that just not change anything.

The reason why they don't do this actually in a competition, and give you a relatively short scrambling, is because it would take more time to figure out a scrabling for yourself, or using your way too long (50-60 moves) scrambling. Unnecessarily. A competitor usually do many scrambling during that one hour.

Again: 20 moves of scrable = 21 moves of solution. 200 moves of scramble = 21 moves of solution. Unknown scramble = 21 moves of solution. The only difference is how much time would it take to find that solution.
 
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