I am shocked. Today, just now. I got another 19 move single. I am so surprised.
Today, I started my practice solves with a 30, and then a 28, which aren't particularly good, and then I got this. A 19.
This is my 3rd ever sub-20, which tied my personal record for the second time, at 19 moves.
This is the reconstruction:
1/5/2020 2:23 - Scramble: R' U' F U D F' L' U2 R B2 R D' F' R2 U2 L' D2 L F2 L' U2 L2 D2 F2 R' U' F
L D' B' R // EO + DR-4c2e (4/4) This was by far the most crucial part
R2 U' R2 B' // Domino (4-1=3/7)
R2 D' U' L2 // Blocks (4/11)
U D F2 U' R2 * // All But 3c (5/16)
*= R2 U L2 U' R2 U L2 U' (8-4=4/20)
L D' B' R' U' R2 B' [R2 D' U' L2 U D] F2 L2 {U' R2 U} L2 U'
Replace, [] -> R2 D2 B2 D2 (4-5=-1/19)
{} -> D' F2 D (3-3=0/19)
Final Solution: L D' B' R' U' R2 B' R2 D2 B2 D2 F2 L2 D' F2 D L2 U' (19)
I did use all of my hour of time. In fact, I finished writing the U' at about two seconds before my timer sounded, so it would really be an understatement to say it was a close call. It was really, really close.
At the beginning of the hour, I found some nice blockbuilding, a 2x2x3 in only 7 moves, but I couldn't find anything else. I spent way too much time trying to make it work. Although, before I found the 2x2x3, I noticed I did have only two bad edges for EO, but I dismissed it as they were on opposite corners on both regular and inverse scrambles.
Once I tried everything I could with the blocks, I returned back to the two edges, and I realized there were eight possible ways I could orient these edges in four moves, meaning that some ways are luckier than others, so I tried them and saw which gave the best domino reduction. This is a bit of a random note, but I would say that getting eight possible four move EOs is actually better than a single two move EO, because of the forced better continuation from one of them being better than others. anyway, I checked for domino on U/D and R/L, but I did not find an incredibly easy DR on R/L the same way I did on U/D, which, I thought for a second was 8 moves long, but it took me a second to realize the R's cancel so it is a 7 move domino. I'm not sure why I didn't see that straight away, and that's why it's written that way in the explanation.
Now, after domino, I found some way to get to 2e2e in only 19 moves, and I used the inverse scramble, NISS, and when I wrote out my skeleton, my 2e2e was set up right as the end of it perfectly, (exactly like the 3c insertion in my final solution) so it was what we call a "lol insertion", which easily resulted in a 25 move solution. If I ended the solve there, I would be satisfied by the fact that it is 25 moves, but I actually would not be satisfied because I would have felt that I sort of wasted my seven move domino. So, I continued my search for a better solution. (Spoiler alert, it was better than 25.)
Now, after domino, I noticed that R2 built a couple of pairs in one move. D' created two squares, but it was with the E-layer edges, which hardly even counts, all you should count is U/D, but I did anyway, but only because I knew fully that I could correct it with slicey shenanigans if needed, so I knew I was not wasting any moves at all. I then did U' L2, which easily intuitively led to U D F2 U' R2, which solved everything except for three corners.
Once I reached this point, I began my insertion immediately. Because I just got to AB3c, I was at the very end of my skeleton, which I'd be there anyway because I always search for all of my insertions starting from the end at working towards the beginning, anwyays, I immediately saw that a corner commutator interchange starts with R2, which means I already cancelled two, and my inserting sequence is U L2 U', which cancels an additional two moves. This is the exact moment I knew I had a 20 move solution.
20 moves. Incredible, I thought to myself. I was even shocked at that. Twenty moves is insane. Seriously. It really is such an outstanding result, and no one can deny that. Although, I still had just a couple minutes left. I don't know the exact amount, but it was definitely under four minutes, and probably under three. I got to work.
I looked at my skeleton and and figured out if, and where, I could reduce it. My eyes went directly to the R2 D' U' L2 U D, because it has two pairs of consecutive pairs of moves on the same axis, (either R/L, or F/B, or in this case, U/D) so I did the inverse of it and saw what I could do instead.
I tried R2 D2 B2 D2, and saw that it didn't solve everything, it left three of the middle slice of edges. I now had to search for where I could solve the 3e for free, so I was on the lookout for a pair of U/D moves connected by a double face turn that were going in opposite directions.
For example, U F2 D or D' L2 D, but not U F2 D' or D' L2 D2. This is the system that I had devised just from personal experience. It's not some crazy breakthrough or anything, just a little handy tip that saves time and effort, which is exactly what I needed.
I spotted U' R2 U, and I used rNISS, or whatever its called (is it?), to go directly to that point to see exactly what's going on.
This is the exact moment I knew I had a 19 move solution.
I applied the moves D' F2 D, which solved the cube, and I wrote down my final solution just in time:
Final Solution: L D' B' R' U' R2 B' R2 D2 B2 D2 F2 L2 D' F2 D L2 U' (19)
That, my friends, is my tied fewest moves record, explained.
I took over an hour to write this. Lmao. I'm so slow.
I am obviously very happy about this result. I'm done for today. This is amazing. Nineteen. Just wow.