# 48 puzzle blindfolded by Yuichi Hamada in 48:52.41[5:32.88]

#### abunickabhi

##### Member
World's first success in 48 puzzle blindfolded (7x7 slide puzzle) by Yuichi Hamada in 48:52.41[5:32.88].

Super interesting thing to attempt, I have seen people do 15 puzzle blindfolded a lot, but doing a bigger puzzle and that too not on slidysim is super cool.

PS: He is a 40+ cuber and regular competes in blind events in Senior Cubers Worldwide FB comps.

#### pjk

Staff member
That is awesome and impressive. I don't think I've seen a 48 puzzle before.

#### cuber314159

##### Member
Very impressive, it is a bit confusing watching it as he seems to be doing the middle column first but then I would have no idea where to start, when solving 48 puzzles I do it row by row but if he had done that then simply moving the first 1 into its spot would move so many other pieces that would have to be tracked.

#### Kurukuru

##### Member
That is awesome and impressive. I don't think I've seen a 48 puzzle before.
Thank you! 48 puzzle BLD is so interesting. (I am the one in the video)

Very impressive, it is a bit confusing watching it as he seems to be doing the middle column first but then I would have no idea where to start, when solving 48 puzzles I do it row by row but if he had done that then simply moving the first 1 into its spot would move so many other pieces that would have to be tracked.
Thank you! (I am the one in the video)

The method is very simple, which is two-point exchange same as M2 method. (1)Memorize the order of the numbers, starting from a fixed position ([48] in my case.), and (2)according to the memorized order, move the piece to the buffer position ([40] in my case.), following the simplest path (right move first and down move next in my case), (3)exchange two pieces between the fixed position and the buffer position. (4)move back the original position following the reversed path of the simplest path. (Up move first and left move in my case.) (5) exchange two pieces between the fixed position and buffer position again.

Repeat (2), (3), (4), and (5) in the order of (1).

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#### Melvintnh327

##### Member
Very impressive, it is a bit confusing watching it as he seems to be doing the middle column first but then I would have no idea where to start, when solving 48 puzzles I do it row by row but if he had done that then simply moving the first 1 into its spot would move so many other pieces that would have to be tracked.
I find using row by row harder on bigger cubes puzzles, so what I do is I solve everything except the last two rows, then I solve the last two rows column by column.

#### Jacck

##### Member
Thank you! 48 puzzle BLD is so interesting. (I am the one in the video)
Very impressive! Your memo-time was very fast.
I just own a 15-puzzle and because I am very bad at it sighted I do it blind since a while in the weekly competition here.

#### Kurukuru

##### Member
I find using row by row harder on bigger cubes puzzles, so what I do is I solve everything except the last two rows, then I solve the last two rows column by column.
It's interesting.

Very impressive! Your memo-time was very fast.
I just own a 15-puzzle and because I am very bad at it sighted I do it blind since a while in the weekly competition here.
I do memory sports (number memorization), which help me a lot.

#### Jacck

##### Member
I do memory sports (number memorization), which help me a lot.
Though I know and use a double-digit majorlist, I'm not fast at it (best was sub 6 min for a deck of cards // about 5 min for 100 digits).
I use it for Megaminx blind (60 possible states for corners or edges): a double-digit number for one piece. Perhaps you should give Megaminx blind a chance

#### Kurukuru

##### Member
Though I know and use a double-digit majorlist, I'm not fast at it (best was sub 6 min for a deck of cards // about 5 min for 100 digits).
I use it for Megaminx blind (60 possible states for corners or edges): a double-digit number for one piece. Perhaps you should give Megaminx blind a chance
I have not come up with the idea of Megaminx blindfold, which sounds challenging and fun. Although I need to think about the numbering mechanism for Megaminx very carefully, the amount of memory required may not be a big issue. However, I don't have any idea how to exchange pieces. I will think about it. Anyway, thank you

#### Jacck

##### Member
I have not come up with the idea of Megaminx blindfold, which sounds challenging and fun. Although I need to think about the numbering mechanism for Megaminx very carefully, the amount of memory required may not be a big issue. However, I don't have any idea how to exchange pieces. I will think about it. Anyway, thank you
On 3rd of June 2016 I explain in two different posts my numbering mechanism and my method for edges and then corners.

For edges I now normally use my method with this X-perm: L' R' U2 L U R y L R U2' R' U' L' y'
My buffer now is left-back.
If it is easy possible, I setup for the other method to solve two edges at once (I bring one edge to 1 and "interchange" with U2' and U2).

#### Kurukuru

##### Member
Yuichi did another crazy thing today.
He reconstructed a QR cube blindfolded on a layer using MBLD cubes.

Thank you for sharing! I will continue to challenge BLD something.

#### White KB

Yuichi did another crazy thing today.
He reconstructed a QR cube blindfolded on a layer using MBLD cubes.

The question is: What happens when you scan it?
(I don't have a phone and so also can't scan QR codes, so I wouldn't be able to figure it out anyway.)

#### Kurukuru

##### Member
So... exec is like in OP on 3BLD, but 2-dimensional and with no algs?
It is not so difficult.

I convert three binary information to one number(e.g, from 010 to 2, 101 to 5). Thus, a binary representation of one face of cube corresponds to 3 digit numbers. 25x25 size QR corresponds to approx. 200 digit numbers. I memorize these numbers. (I do memory sports so not very difficult to do this memorization.) And do BLD execution by using the attached simple algorithm,

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