Hi everyone, to fix the parity I use a method I'm sure you know but I'd like to remember it to you because in any cases you only have to do one parity alg.
When I've solved the F2L I look if there is a Oll parity or not. 1°) If not you do the OLL and then PLL (with sometimes the PLL parity) 2°) If there is a OLL parity problem, you do an OLL so that only one edge remains flipped(you can choose the OLL between several of them, and choose the shortest one). Then you can easily see if there is also a PLL parity or not, and you do the OLL parity alg or the both parity alg depending on the situation. So you have zero or one alg to do. I use this method (like Yuki) since a long time and it wokrs pretty well. You've almost no break after little practice. And it seems easier than learning COLL or something else. What do you think of that? Olivier --- In [email protected], "Craig Bouchard" <[EMAIL PROTECTED]> wrote: > > YES... > > HEHE...I couldn't apply this but maybe: > > Have an alg for the OLL parity, and have an alg for the OLL parity > when it is 3 edges...and then do a COLL case to solve the corners, and > leave the edges to be permuted...The way I do my LL is 4LLL, so I've > never gotten one of the corner PLL parities...i'm kinda happy about > that...not sure which is faster...cuz if you do: 1 alg for edges > (1,2,3,4) then COLL, then PLL edges (then fix PLL parity if needed) I > think that would be quite fast... > > Craig > > --- In [email protected], cmhardw <no_reply@> > wrote: > > > > Hey everyone, > > > > I have a new LL strategy for centers first people to propose and > > analyze in this post. I am trying to come up with new ways to handle > > the parities on a 4x4, and am requesting we put our brains to this task. > > > > Here is the idea, to only have the double parity (meaning do an alg to > > fix the orientation parity, then do an alg later in the solve to fix > > the permutation parity) 1/8 the time instead of 1/4. To do this break > > the orientation parity cases into 2 groups. > > > > 1 oriented LL edge: > > Do either the parity alg or double parity alg leaving a 50-50 chance > > to also have PLL parity so to encounter double parity here is a 1/8 > > chance overall. > > > > 3 oriented LL edges: > > Do a COLL alg, now recognizing whether the 3x3 edge groups have the > > same parity as the corners is very easy. So if you have double parity > > do the double parity fix pure version, if not do the regular parity > > fix pure version. > > > > So that means only 1/8 the time you do 2 algs. Now don't get excited > > yet, this method stinks. > > > > Here are the times for each LL strategy (for me). I did an average of > > each alg. > > > > permutation parity fix: > > 02.34, 02.24, 02.63, (03.28), 02.44, 02.73, 02.68, 02.23, 02.43, > > 02.90, 02.79, (02.11) = 2.54 average > > > > orientation parity (speedsolve version - double parity alg): > > 04.94, 04.47, 05.34, 04.91, 04.65, 05.03, 04.42, 04.45, (04.18), > > (05.52), 04.97, 05.29 = 4.85 average > > > > double parity alg pure version: > > 06.23, 07.56, (06.02), 08.10, 06.50, (08.24), 08.02, 06.71, 07.64, > > 07.33, 06.42, 06.24 = 7.07 average > > > > orientation-parity-only alg pure version > > 06.06, (05.98), 06.79, 06.75, 06.77, 06.38, (08.66), 06.51, 06.41, > > 06.66, 07.40, 07.60 = 6.73 average > > > > So here is the analysis of the extra time spent on average just fixing > > parities: > > > > Conventional method with 1/4 double parity: > > > > 0.25*0 + 0.25*2.54 + 0.25*4.85 + 0.25*(2.54+4.85) = 3.70 seconds on > > average to fix parities. > > > > ----- > > > > and with the new 1/8 double parity method > > > > 0.25*0 + 0.25*2.54 + 0.125*(4.85+2.54) + 0.125*(4.85) + 0.125*(7.07) + > > 0.125*(6.73) = 3.89 seconds on average spent fixing parities. > > > > Also solving with the new way I have to do COLL vs. OLL 1/8 the time > > which is probably 1 second longer. So 1/8 second overall. Making the > > 3.89 actually 4.02 seconds. > > > > In order to make this faster than the conventional approach I would > > need to solve the pure version double parity alg (x) and the pure > > version orientation-parity-only alg (y) in: > > > > 3.70 = 0.25*0 + 0.25*2.54 + 0.125*(4.85+2.54) + 0.125*(4.85) + > > 0.125*(x) + 0.125*(y) + 0.125 > > > > 2.94 = 0.125*(12.24 + x + y) > > > > 11.28 seconds = x + y > > > > Which means the sum of both pure alg versions has to be 11.28 seconds > > or less. > > > > We can assume that x can be no faster than 4.85 and y can be no faster > > than 5.55 which is my average for the speed solve > > orientation-parity-only alg (again this analysis is done with my > > times, since those are the only available to me right now). > > > > 05.82, 05.38, 05.11, 05.82, 05.54, 05.58, (04.75), (06.07), 05.57, > > 05.52, 05.74, 05.39 = 5.55 seconds > > > > So that means there is only a give room of about 0.8 or 0.4 seconds > > per alg. Meaning that my pure version double parity alg can only be > > 0.4 slower than my speed solve version and same for the > > orientation-only-parity algs. I don't think that's possible for me. > > So in conclusion again, this method stinks. > > > > But can we somehow reduce the 1/4 chance to do both parities and, for > > me, take 7.39 doing nothing but fixing parities. I mean come on that > > amount of time is ridiculous. Added on to a solve that would > > otherwise have been 55 seconds means that 11.91% of the solve is > > fixing parities. Fixing parities. That's ridiculous, we shouldn't > > have the standard accept that as ok. > > > > Can we take anything from this and form a different, better strategy? > > Any ideas? My only idea so far is to use the COLL case when you have > > orientation parity to guess the corner permutation and then compare it > > to the edge permutation. I think that is fairly thought intensive > > though, so the amount of decision time required could actually make > > that strategy take more time fixing parities on average. Alright, > > well I'm trying to think of something new, anyone else have ideas? > > > > Also, should the centers first method be scrapped entirely in favor of > > a cage method? That would allow me flexibility to fix the orientation > > parity (the only one!) and also commutators are very easy to come up > > with on the fly once you have practice and experience with them. So > > with mastery it seems to me that maybe a cage method is a better > > choice in the long run than a centers first method. > > > > Fixing parity sucks, but the fact that the edge permutation is > > completely independent of the rest of the cube (!) is what makes the > > 4x4 so cool in my opinion :-D > > > > Chris > > > > P.S. If you actually made it to the end of this post congratulations. > > I know it's long, but I want to come up with a better way to handle > > the 4x4 parities. Even if it only saves 0.5 second on average, that's > > still time saved. Thanks for your time spent reading. > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/speedsolvingrubikscube/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
