People · Republic of Korea
Seongjoo Jeong (정성주)
3×3 · top 4.7% of 284,439 all-time · competing since December 2017 · 2017JEON03
Seongjoo Jeong (정성주) has been competing for 9 years. His best event is the 3×3: a personal-best single of 8.95, set at Hamoye Jinju 2026, puts him in the top 4.7% of the 284,439 people who have ever been ranked in the event, and 282nd in Republic of Korea. Until May 2008, no official 3×3 solve in the world had been that fast. Across 6 competitions since December 2017, he has put 203 official solves on the record across eleven events. Solve to solve, his 3×3 times vary about 8% around a typical one, an early reading from 6 counted rounds. His 4×4 best has come down from 40.48 in July 2025 to 33.91, a 16% improvement. Seongjoo has entered six competitions, more competitions than 86% of everyone who has ever competed.
Standing, event by event
vs everyone ever ranked| Event | PB single | PB average | All-time standing | Republic of Korea | |
|---|---|---|---|---|---|
| 3×3 | 8.95 | 10.79 | top 4.7% | 282 / 4,352 | |
| 4×4 | 33.91 | 37.36 | top 5.8% | 124 / 1,308 | |
| 5×5 | 1:00.76 | 1:15.49 | top 5.9% | 67 / 716 | |
| 3×3 one-handed | 14.64 | 16.89 | top 7.4% | 101 / 966 | |
| 2×2 | 2.70 | 3.73 | top 10.9% | 320 / 2,319 | |
| Pyraminx | 5.68 | 7.57 | top 17.6% | 278 / 1,271 | |
| 6×6 | 2:15.92 | 2:26.37 | top 18.5% | 88 / 329 | |
| Skewb | 5.45 | 6.34 | top 21.6% | 219 / 854 | |
| 7×7 | 3:55.10 | 4:14.61 | top 28.9% | 101 / 254 | |
| Square-1 | 23.96 | 29.11 | top 36.7% | 166 / 371 | |
| Clock | 15.90 | — | early days — 3 solves | 350 / 536 |
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
Best single per competition, 4×4. Faster is higher — the axis is the right way up.
The story so far
- 15 Aug 2026Five personal bests in one day at Korea Open 2026.
- 16 May 2026First sub-10 3×3: 8.95 at Hamoye Jinju 2026.
- 16 May 2026Six personal bests in one day at Hamoye Jinju 2026.
- 21 Feb 2026Four personal bests in one day at Cube Camp in Jeju 2026.
- 13 Jul 2025First sub-15 3×3: 11.91 at Suwon Summer 2025.
- 30 Dec 2017First competition: Korean CWR Style 2017. A 15.43 3×3 single to start from.
Competitions
- Korea Open 2026 · 15 Aug 2026 — 5 personal bests set
- Seoul Summer 2026 · 19 Jul 2026 — 1 personal best set
- Hamoye Jinju 2026 · 16 May 2026 — 6 personal bests set
- Cube Camp in Jeju 2026 · 21 Feb 2026 — 4 personal bests set
- Suwon Summer 2025 · 13 Jul 2025 — 2 personal bests set
- Korean CWR Style 2017 · 30 Dec 2017
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.
- Ko Youngjin (고영진) — met in 41 rounds, finished ahead 16 times
- Choi Goho (최고호) — met in 39 rounds, finished ahead 30 times
- Yunsung Nam — met in 37 rounds, finished ahead 3 times
Next targets
- A sub-8 3×3 single — 7,931 people have one; it is 0.95 away.
- A sub-30 4×4 single — 2,388 people have one; it is 3.91 away.
Targets move as he improves.