3 years ago

I'm frequently asked about my thoughts on the limits of speedcubing. Are we almost there, or is there still a way to go? What times are possible on different sized cubes and other events? I've decided to explore these types of questions in this blog post, and share my thoughts and opinions.

I’ll begin with the standard 3x3 cube. A speedsolve has two determinants - move count, and turning speed. For example, a 60 move solution executed at 10 turns per second (TPS) will yield a 6 second solve, and a 40 move solution executed at 8 TPS will take 5 seconds. In my opinion, the upper limit for turning speed is probably 11-12 TPS on average with the CFOP method and its accompanying subsets and variants. This is based on both experience and observation - at the end of the day, there are physical restrictions to turning speed. Of course, it’s possible to achieve higher TPS on individual solves if the solution is rotationless, finger-friendly, or easy to execute in any other way. I’ve also assumed near-perfect lookahead in this 11-12 TPS number, which I believe is definitely possible. However, I still think there’s a lot of room for improvement in the lookahead of even the top speedcubers, particularly in early F2L pairs, and especially for the recognition of last layer cases. We're a long way off 11 TPS.

On move count, that’s an entirely different story. There also exists a massive trade-off between TPS and move count. That is, efficient solutions for solving the cube are often difficult to execute at a high speed. Additionally, looking and thinking ahead also becomes far harder as solutions become shorter, as generally these solutions require more active thinking during a solve. Ideally, a speedsolve should be entirely subconscious and automatic. CFOP has been heavily optimised since its early days, and from my perspective, most significant discoveries have already been made. It sounds a bit pessimistic, but I don’t believe there is anything that can revolutionise CFOP solve times in the way that things such as ZBLL, COLL, OLLCP, WV, VLS, and other subsets have done. Any improvements now will probably be very marginal. Brest (Rob Stuart) kindly reconstructed an average of 100 I posted a little while ago and found my average move count to be 58 STM (Slice Turn Metric) and 62 ETM (Execution Turn Metric) respectively. I certainly think this could go down to the low 50 range with more intelligent solutions and knowledge of more last layer algorithms.

For CFOP, hypothetical average TPS of 11-12 and average move counts in the low 50s suggest the potential for global averages around the 5 second mark. I believe this is theoretically possible, but the dedication required to get to that level is ridiculous. Time will tell - it might take decades for someone to actually achieve this. As speedcubing grows, the talent pool increases, and I wouldn't be surprised if the person who achieves this hasn't yet started speedcubing at all.

There is also an entirely separate debate on the advantages and disadvantages of CFOP and the Roux method. Many suggest that the Roux method has even more potential than CFOP, given its lower move count on average. Again, it comes back to the trade-off between move count and TPS - if we accept that Roux solutions are more sophisticated/complicated and potentially require more lookahead ability, then all things being equal, the TPS of those solves will likely be lower. A question I have for readers is, do you think it is realistically possible to achieve the same TPS (STM) in a Roux solve as opposed to a CFOP solve, and why or why not? In my opinion, the methods have similar overall potential - it would have been interesting to see a speedcubing community evolve in which the majority of members used the Roux method.

Taking a quick look at the Evolution of Records page on the WCA reveals something akin to an exponential decay function, where various 3x3 rankings are charted over time. Improvement in the early years of the graph can be put down to improvements in hardware and methods, and now the gradient of the graph is gradually flattening out. The world record single has dropped only 0.93 seconds since the middle of 2011, and the world record average just over 1 second in the same time frame.

Enough waffle, it’s time to make some actual predictions!

The official single world record for 3x3 will eventually become scramble-dependent. It will remain prestigious and never get silly like the 2x2 single, but I believe that one day it will be virtually unbeatable. A single under 3 seconds in competition is possible, eventually. Even the world record average will ultimately get to the stage where top cubers need to execute an easy set of scrambles particularly well to break it. I’m not sure if we’ll ever see a sub 5 average in competition, but sub 5.5 will definitely happen, my guess is before 2020. I also predict that the WR average will be sub 6 by the end of 2018. Records are still broken extremely frequently in WCA competitions, and I think that there will come a time (in the distant future) when the focus becomes less on records, and more so on winning major competitions and titles, as is the case in many other sports/competitive hobbies which have a far longer history than speedcubing. Globally, I think a sub 5.5 average of 100 is possible way way down the track, if there are enough cubers pushing and challenging one another to achieve it. Speedcubers have always found a way to break barriers which were previously believed to be unbeatable. When I began speedcubing, a sub 1 5x5 single was considered almost impossible. Now, sub 40 is possible.

Throwing out some wild guesses for other events:

4x4: A lucky single around 16-17 seconds will eventually be achieved, and averages will peak at 21 seconds or so.

5x5: A sub 40 single is possible (perhaps imminent!), as well as averages below 45 seconds.

6x6: As the cubes get bigger, it's harder to make accurate predictions. I don't think a sub 1 single is possible on the 6x6, 1:10 might be about the limit with some luck. Low 1:20 averages are probably achievable.

7x7: Someone will get an unofficial sub 2 single in the next 12 months or so I'm pretty sure. However, I don't know if that implies sub 2 averages are also possible.

I might write up a blog post at some other time about the evolution of hardware for big cubes, and significant milestones and events in those events, as I believe it's very interesting.

3x3 OH: I think we'll definitely see people reach sub 10 global averages, but perhaps not too much further.

Let me know what you guys think about the limits of speedcubing!