Roux: Fastest Way to Recognize 4c! (DFDB system)

No pauses, no peeking: speed up the last step of Roux with DFDB recognition.
Download diagram here: drive.google.com/file/d/1soza...
Bonus tip (UFUB): the system also works when solving the UF and UB edges, instead of UL/UR!
For non-matching centers, if the two mismatched stickers are adjacent colors, solve it like a matching center case.
If the two stickers are opposite colors, solve it like non-matching centers except instead of aligning the corners, do either a U or U' (it doesn't matter which, and you get to choose between a stacked or diagonal case).
Either way, when raising the dot there can now be three different colors on the top. Treat the two adjacent-colored stickers as the same, so the third sticker is the dot.
Bonus tip (MC): the system even works for misoriented centers! Track a pair that share a front/back color, rather than a top/bottom color. The rest of the DFDB method works exactly the same as normal.
Credits:
- ‪@GodCubing‬ made a tutorial that showed either DFDB or UFUB edges can be tracked, and I got the term "friend" edge from him too
- ‪@UNOFahmiAR‬ for reviewing drafts of this video and suggesting improvements such as showing many types of 4b inserts not just M2
Chapters:
00:00 Intro
00:52 Tracking friend edges
02:25 Non-cycles
04:34 Cycles
06:26 Matching centers
10:00 Non-matching centers (stacked)
11:56 Non-matching centers (diagonal)
13:51 Summary

[@Hacobbe]

I finallt got this. Thanks so much mate!

[@fredkaboom]

Great explanation! I like that you included non-M2 inserts.

[@jasonbest1]

Brilliant video! I love your addition of the flow chart diagram!

[@ottercuber]

I've struggled with this step, so this was so helpful, thanks

[@ThePowerOfZZ]

I’ve started Roux 2 weeks ago and I average 34 and my PB is 21 ! I’m better than I was with LSE with many solves but I was tilting the cube everytime to search for pieces.. but this 4c method is so useful wow I will start to practice this for sure 👌 I found this video after seeing your video on ZZ eo just for fun because I don’t do ZZ (not for the moment at least) but I try to learn new stuff 😋 I try to switch to Roux after 3 years of CFOP with an average of 15-16 seconds and 9,26 PB. Thanks for your high quality videos 🙏

[@davve14]

Very good explanation. Top 4c the explanation I put on UA-cam 👍.

[@RomanVman]

brilliant video

[@kiraPh1234k]

Interesting that this has a special name. This is just a portion of intuitive LSE for me, but skips all the cases where you did UF/UB before UL/UR -- and I use both styles of pairing because you can do EOLR/EOFB increasing chances for a short LSE

[@Kantstoner]

Outstanding explanation! I watched the other good vid on this a while back, but I just couldn't really get it to work. Maybe I'll switch to Roux for OH again...

[@lyoug]

Thanks for the video and the flowchart, helped a lot!
Quick question: with more complicated inserts (11:10 and 12:46), how do you know whether you have a matching centers case or a non-matching centers case?

[@err0rcuber]

Thank you, glad I could help!
To start out, you can check for matching/non-matching center right before the last move of the insert. If you're lucky and a friend edge will end up at the bottom-front, you can even check it after the last move. Whether front center matches the front-bottom sticker. Initially this will require a pause, but over time your piece awareness will improve and you can see this in advance.
Another, more indirect way is called "deduction":
If the friend edge (that goes to the bottom) needs to be compared with the back center, but you cannot see the back center: instead, look at the top friend edge and the front center. - If they match, so do the bottom friend edge and the back center, so we have a matching centers case.
- If not, then neither do the bottom friend edge and the back center. That's a non-matching center case.
This works because every pair of friend edges has one edge that matches the front center, and the other that matches the back.

[@damianq9884]

Thank you bro I'm finally sub 15

[@baenmarq]

I have a sub 10 official avg and ive still been pausing to check the bottom

[@thoperSought]

that's absolutely excellent!!
is the chart available anywhere?

[@err0rcuber]

thanks!
here's a link to PDF of the diagram: drive.google.com/file/d/1sozaJ1U2Xz4VL5PDUJCyt3gYsPZP4hay/view?usp=sharing
I've added it to the description just now

[@thoperSought]

@@err0rcuber awesome!! thank you very much!!!

[@mdaffailhami]

What about the UL & UR edges at the DF & UB? In that case I can insert the UL & UR edges with M U2 M or M' U2 M. Or I should just put the UL & UR edges at the bottom so I can insert them with M2?

[@err0rcuber]

insert with M U2 M or M' U2 M
DFDB works with many kinds of inserts, not just M2
see 9:15 for an example