# M2 middle slice edges help?



## mkarthick (Aug 19, 2014)

Hello, I'm new to blindfold solving, and I decided to learn M2/3OP because I wanted to be fast. I've understood and learn M2 almost completely, but I have a problem with the *edges on the middle slice*. The edge almost never ends up where I want it to. The algs are fine, I've checked them. I think the problem is because of the rotation of the middle slice every time, so the edge is in the wrong place when I'm done. How do I avoid this?


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## ChickenWrap (Aug 19, 2014)

You need to memorize your targets in pairs so you can determine the orientation of the middle slice. For example:

at ue op bs uf 

So if you have a T in your memo (like above), you would know the M slice is off so you use the opposite alg for the edge. Just mess around with it with your eyes open, its not too difficult if you take your time.


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## Berd (Aug 19, 2014)

mkarthick said:


> Hello, I'm new to blindfold solving, and I decided to learn M2/3OP because I wanted to be fast. I've understood and learn M2 almost completely, but I have a problem with the *edges on the middle slice*. The edge almost never ends up where I want it to. The algs are fine, I've checked them. I think the problem is because of the rotation of the middle slice every time, so the edge is in the wrong place when I'm done. How do I avoid this?



I'm no expert; (First success today using M2/OP) But I think you know your problem. If the letter on the M slice appears on the second letter in the pair (assuming you're using letter pairs) eg: "A I" or "D C" then you have to do the opposite of that letter. Example: "M C" would actually be executed as "M W" and "D S" would be executed as "D I". However if "A" or "Q" come in the second letter of the pair EG: "B A" or "W Q" then you would execute it normally. I'm assuming you are using the Speftz letter scheme or everything I've just said is useless :/ If a more experienced blind solver could back me up or correct me that would be great.

EDIT: This post didn't have any replies when I started But it did when I finished.


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## Sessinator (Aug 19, 2014)

mkarthick said:


> Hello, I'm new to blindfold solving, and I decided to learn M2/3OP because I wanted to be fast.



I would recommend learning OP corners over 3OP. OP is nice and simple to memo and execute, and you can get relatively fast with it. With OP corners you basically have "sticker" memo where you memorize which "sticker" on the corner to shoot to. With 3OP you have to worry about memorizing the orientation of the corners that you need to flip and the positions of the cycles that you need to perform. Also, if you get to the point where you want to go faster and switch to 3style/comms/freestyle you will be using sticker memo anyway.



mkarthick said:


> I think the problem is because of the rotation of the middle slice every time, so the edge is in the wrong place when I'm done. How do I avoid this?




When you memo edges for M2, it makes sense to memo and recall the memo in pairs or in even groupings. This is because with M2, you are setting up an edge from your buffer to the UB position, performing M2, then undoing the setup move. What has occurred is that you have solved one piece, but you are now off by an M2. Once you solve the next piece in your buffer (set up to UB, M2, undo set up), the M-slice is restored (since M2 has been performed twice). 

Working with the pieces on the M-slice can be tricky at first, but once you know what to do it's rather simple. If the M-slice is off (or if you are at an even position in the cycle), you need to account for that and shoot to the appropriate spot.

If I memorized CKOP RTVL, the odd positions (where the M-slice is not off) are CORV, and the even positions (where the M-slice is off) are KPTL.

If you have are at an *odd* spot and have to solve an M-slice piece in your buffer, the M-slice is fine. Perform the normal alg for M-slices. 
If you are at an *even *spot and have to solve an M-slice piece in your buffer, take note that the M-slice is off. Recall the earlier example. You set up a piece to UB did M2, and undid M2. Now you have your even position in the buffer and your M-slice is off by an M2. Instead of shooting to UF, you will need to shoot to DB because the appropriate position you want to shoot to is now in DB position because you are off by an M2 from solving the former piece. Same goes vice versa (if you are at an even position and you want to shoot to DB, you really have to shoot to UF). Same also goes for some of the other pieces on the M-slice if you are in an even position. For FU, you will have to shoot to BD, and vice versa. 

The nice exception with the M2 method here is UB. If you need to shoot to UB, no matter where you are (odd/even position) you will just need to perform M2 to solve it. This is because in relation to your buffer, DF, the UB position is always an M2 away, so being an "M2" off doesn't really affect this. Try it out yourself if you don't understand to see how it works. It would probably help to take some time to mess around with the M-slice in general so you can get familiar with whats going on.


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