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The Middle Three
People → Hong Kong, China → Zhou Zi Kai (周子凱)

People · Hong Kong, China

Zhou Zi Kai (周子凱)

Pyraminx · top 1.7% of 129,321 all-time · competing since May 2023 · 2023KAIZ01

Zhou Zi Kai (周子凱) has been competing for 3 years. His best event is the Pyraminx: a personal-best single of 2.30, set at Hong Kong Championship 2025, puts him in the top 1.7% of the 129,321 people who have ever been ranked in the event, and 14th in Hong Kong, China. Until July 2011, no official Pyraminx solve in the world had been that fast. Across 21 competitions since May 2023, he has put 569 official solves on the record across ten events. Solve to solve, his 3×3 times vary about 14% around a typical one; 76% of the 35,811 competitors with ten or more counted rounds hold a tighter spread. His 3×3 best has come down from 24.68 in May 2023 to 7.84, a 68% improvement. Zhou has entered 21 competitions, more competitions than 97% of everyone who has ever competed.

Pyraminx
best event — top 1.7% of 129,321 all-time
2.30
signature single · Hong Kong Championship 2025
569
official solves on the record
14%
solve-to-solve spread · wider than 76% of the field

Standing, event by event

vs everyone ever ranked
EventPB singlePB averageAll-time standingHong Kong, China
Pyraminx2.303.07
top 1.7%14 / 431
3×37.8410.14
top 2.5%65 / 1,347
2×21.983.49
top 4.6%61 / 855
4×444.3152.94
top 17.4%129 / 423
Skewb4.947.36
top 17.7%71 / 285
3×3 one-handed20.0322.80
top 20.5%128 / 361
5×51:53.092:15.03
top 44.7%122 / 192
Megaminx2:08.482:36.62
top 50.4%105 / 154
Clock17.5428.36
top 57.3%114 / 156
3×3 Fewest Moves47 moves—
early days — 1 solve65 / 76

Percentile against all competitors ever ranked in each event, a fairer measure than raw rank, because the pools differ by a factor of ten.

The line so far

Hong Kong Small Cube Day 2023: 24.68Taiwan Cubing Challenge 2023: 18.28Chemung Cubing 2023: 13.25Hong Kong Championship 2023: 14.30Cubing Battle of Katipunan 2024: 9.33Xuzhou Open 2024: 11.86Welcome Back Hong Kong 2024: 10.49Shenzhen Nanshan Open 2024: 9.36Minnesota Warm Up 2024: 9.08Rubik's WCA North American Championship 2024: 9.25Hong Kong Cube Day 2024: 9.96Hong Kong Championship 2024: 8.66Shenzhen Open 2024: 8.13Hangzhou Open 2024: 8.05Chengdu Spring Open 2025: 7.84Hong Kong Cube Day 2025: 9.39Hong Kong Championship 2025: 8.64Foshan Open 2026: 8.857.8424.6826 May 20232 May 2026

Best single per competition, 3×3. Faster is higher — the axis is the right way up.

The story so far

Competitions

Reading this page: a single is one solve's time · an average is the middle three of five solves, best and worst discarded · a PB is a personal best · a DNF (did not finish) is an attempt with no valid result: a popped piece, an unsolved face, an over-limit memorisation · top X% compares against everyone ever ranked in that event, which is fairer than raw rank because event pools differ tenfold.

The circuit

The people whose scorecards keep turning up next to his.

Next targets

  • A sub-2 Pyraminx single — 1,476 people have one; it is 0.30 away.
  • A sub-6 3×3 single — 1,376 people have one; it is 1.84 away.

Targets move as he improves.