# Tips for F2L cross on left



## LarsN (Nov 2, 2007)

This is not to debate if you should keep cross on left or buttom. There are plenty of threads on that topic and I've already decided to do cross on left.

I'm looking for tips from some sub20 cubers who do the f2l with cross on left.

Like...

- do you try to always insert at pairs at UF?
- any special algs for difficult cases?
- what do you look for when looking ahead? (corners in R/edges in R/etc.)
- or any other tips you might have...


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## Marcell (Nov 2, 2007)

LarsN said:


> - do you try to always insert at pairs at UF?


No, also UB and DF.
I'm not consistently sub20, though.


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## Erik (Nov 2, 2007)

I'm not a lefty but I can solve with left in about 14/15 seconds. Mostly indeed I solve in UF but sometimes also in UB or DF if that's easier. Mostly firts find the corner and then the edge belonging to it, Just practise!


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## AvGalen (Nov 2, 2007)

Just find some solves by Lars vdB and watch them in slowmotion. He is the fastest cross-on-left cuber I know and he is on videos a lot.


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## masterofthebass (Nov 2, 2007)

Arnaud, almost all of the top Caltech guys are cross-on-left, except the Dzoans. Mitchell has a few vids from the US Open on his site http://opticubes.com. Ryan, Leyan, Toby, Tyson are all cross on left.


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## AvGalen (Nov 2, 2007)

I didn't know that. I will look at that compilation video a bit more closely to double-check.


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## masterofthebass (Nov 2, 2007)

masterofthebass said:


> Mitchell has a few vids from the US Open on his site http://opticubes.com.



There's videos of toby, leyan, and ryan on there. No need for the compilation vid.


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## ExoCorsair (Nov 2, 2007)

It's all lookahead.

If you look at my F2L page (http://exocorsair.110mb.com/?page_id=48), you will see that most of the algorithms are two-gens, and my normal insertion slot is at UB. This allows me to look at the two slots at UF and DF if I'm not on the last pair. Granted, two-gen algorithms are not optimal and raises the move count up significantly, but I usually average around 11-12 seconds for F2L, and I believe that my fastest F2L is something like 8.8x seconds using these algorithms.


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## LarsN (Nov 2, 2007)

Thanks for your replies. I didn't know that there were that many lefty cubers. I'll study some videos and practise on the looking ahead a lot.

I've tried switching to cross on buttom so many times because I thought it really was faster, but I didn't really get the feel for it. Know that I've seen a few vids of people doing it fast with the lefty way, I'm gonna stick to it and practise a lot to get better.


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## Dennis (Nov 5, 2007)

You probably know that Jess Bonde also solves cross on left, rubiks.dk


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## roinuj2 (Nov 6, 2007)

I need a tip on something that just crossed my mind. If you just finish cross or finish a F2L pair and moving on to a next pair and that pair you find is together but not paired up properly AND is in the wrong slot what is the best thing to do?

a) disconnect the pair then alg them into the correct slot OR 
b) forget them and look for another pair

Thanks


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## ExoCorsair (Nov 6, 2007)

roinuj2 said:


> I need a tip on something that just crossed my mind. If you just finish cross or finish a F2L pair and moving on to a next pair and that pair you find is together but not paired up properly AND is in the wrong slot what is the best thing to do?
> 
> a) disconnect the pair then alg them into the correct slot OR
> b) forget them and look for another pair
> ...



I think it's faster to just do that pair immediately instead of looking for another pair. Other people might disagree with me, though.


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## Todd (Nov 6, 2007)

What made you decide to do cross on the left?


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## AlexandertheGreat (Nov 6, 2007)

use open slot tricks or find the fastest way to take it out and put it in the right slot correctly.

For the latter option, there are certain situations where you can fix the pair pretty quickly. For example, get your cube to a state so that the f2l case to be solved is like #6 on Leyan Lo's site, but the pieces are a slot above where they're supposed to be (do U' R' U x' R' F R' F' R' U' R U when cross is on the left and the FD pair is solved). When I see this, the fastest way that I know how to solve it is with x R' U R2 U' x U R U. When an edge is in the wrong slot and that wrong slot is adjacent (immediately above or below) to it's correct slot, I treat the edge as if it were flipped over. In the above example, I essentially treated the edge as if it were flipped, and thus I used a extension of one solution for case #9 (Leyan's site) I use this technique frequently whenever I get edges that are in the wrong slots while the corners are in the free R layer. It definitely saves a lot of time for me.


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## LarsN (Nov 7, 2007)

Todd said:


> What made you decide to do cross on the left?



Well I learned intuitive f2l without any help from a website or similar. I just figured it out on my own. Then when I went to a site to find algs for the more difficult f2l cases I noticed that they were all for cross on the buttom. It simply came naturally for me to do it on the left, and it still does after I've tried doing it on the buttom. I don't like using my left hand much while cubing, which is something I might need to overcome eventually.


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