Prediction Hub

Lucky-Scramble Forecast: Cumulative Probability of Hitting the Luckiest Scramble

3x3 has 4.3×10^19 states; only 262 (= 1+18+243) are solvable in ≤2 moves. A single random scramble has only ~6×10^-18 chance of landing there. But WCA accumulates many scrambles per year (incl. backups); cumulative-hit probability is P = 1 − (1 − p)^N, monotonically rising with N. Drag the year → see N(Y) → see cumulative probability per depth threshold → see the expected luckiest result.

Year
2026
Cumulative 3x3 scrambles
N(Y) = 6.61M (incl. backups)

Left half (0–40%) is linear 2003–2100; right half is log up to 10^15 yr.

3x3: Cumulative Hit Probability

Through 2026, WCA has accumulated 6.61M 3x3 scrambles (incl. backups). Cumulative probability of at least one d ≤ K hit across these N is P = 1 − (1 − p)^N. Smaller K → smaller p in the 4.3×10^19 state space → need exponentially larger N.

Depth K (moves)# states at d ≤ KSingle-scramble pP(d≤K hit) @ N=6.61MN₅₀ (scrambles)Year reachedTime at d (s, TPS 17)
d ≤ 22626.1×10^-184.00×10^-111.14×10^172.0×10^60.27 s
d ≤ 5621,6491.44×10^-149.50×10^-84.82×10^1341,9960.44 s
d ≤ 81.44B3.33×10^-112.20×10^-420.80B27460.62 s
d ≤ 10251.29B5.81×10^-93.77%119.31M20560.74 s
d ≤ 124.37×10^131.01×10^-699.9%686,21420170.86 s
d ≤ 159.89×10^160.229%~100%30320041.03 s

How to read: e.g. d ≤ 2 row — single-scramble prob 6×10^-18 (262 of 4.3×10^19). Need N₅₀ ≈ 1.2×10^17 to have 50% chance of one such hit; that's ~10^14 yr away at WCA's 7.5M scrambles/year cap. That is why "3x3 2-move lucky solve" is not a near-future event but an asymptotic limit. Today the expected luckiest scramble is d ≈ 11.5 with P(d≤12) ≈ 99.9%.

3x3 · 2026 luck forecast
0.83 s
E[min] = 11.56 moves / 17 TPS + 0.15 s
Cumulative scrambles
6.61M
2003–2026 · incl. backups
Expected min depth
11.56 moves
WCA accepts ≥2 moves
TPS 14.6 (real cuber)
0.94 s
TPS at Wang sustained level

Cumulative Hit Probability vs Year

Each line corresponds to one K threshold. X-axis: log year (2003 → 10^15 yr), Y-axis: P(hit ≤ K). Watch when each line crosses from 0 to 1.

0e+020%40%60%80%100%2003210212,0021.0×10^61.0×10^81.0×10^101.0×10^121.0×10^14Cumulative PYear (log)
P(d ≤ 2)P(d ≤ 5)P(d ≤ 8)P(d ≤ 10)P(d ≤ 12)P(d ≤ 15)

Expected Luckiest Time vs Year (Cross-Event)

Log year vs log seconds. Each line = E[min depth] / TPS_ceil + setup_s per event. Asymptote = k_min_wca / TPS_ceil + setup (fastest physically possible single).

0.010.101.010.02003210212,0021.0×10^61.0×10^81.0×10^101.0×10^121.0×10^14Expected luckiest (s)Year (log)
3x3x32x2x24x4x45x5x5PyraminxSkewb

Per-Event Forecast at Selected Year

★ = exact depth distribution; ◐ = partial (exact low / est. high); ~ = approximate. Time = E[min] / TPS_ceil + setup_s.

3x3x3333◐
Cumulative scrambles
6.61M
E[min] depth
11.56
Expected luckiest
0.83 s
11.6m / 17 TPS + 0.15s
2x2x2222★
Cumulative scrambles
5.62M
E[min] depth
1.00
Expected luckiest
0.16 s
1.0m / 16 TPS + 0.1s
4x4x4444~
Cumulative scrambles
4.63M
E[min] depth
30.55
Expected luckiest
3.35 s
30.6m / 12 TPS + 0.8s
depth distribution approximated
5x5x5555~
Cumulative scrambles
3.64M
E[min] depth
46.64
Expected luckiest
5.44 s
46.6m / 11 TPS + 1.2s
depth distribution approximated
6x6x6666~
Cumulative scrambles
1.65M
E[min] depth
69.91
Expected luckiest
9.27 s
69.9m / 9 TPS + 1.5s
depth distribution approximated
7x7x7777~
Cumulative scrambles
1.32M
E[min] depth
95.00
Expected luckiest
13.87 s
95.0m / 8 TPS + 2s
depth distribution approximated
3x3 One-Handed333oh◐
Cumulative scrambles
2.64M
E[min] depth
11.87
Expected luckiest
1.39 s
11.9m / 10 TPS + 0.2s
Clockclock~
Cumulative scrambles
1.65M
E[min] depth
6.91
Expected luckiest
0.68 s
6.9m / 13 TPS + 0.15s
depth distribution approximated
Megaminxminx~
Cumulative scrambles
1.19M
E[min] depth
45.04
Expected luckiest
6.00 s
45.0m / 10 TPS + 1.5s
depth distribution approximated
Pyraminxpyram★
Cumulative scrambles
3.64M
E[min] depth
1.00
Expected luckiest
0.18 s
1.0m / 13 TPS + 0.1s
Skewbskewb★
Cumulative scrambles
2.64M
E[min] depth
1.00
Expected luckiest
0.18 s
1.0m / 13 TPS + 0.1s
Square-1sq1~
Cumulative scrambles
1.85M
E[min] depth
11.84
Expected luckiest
1.48 s
11.8m / 10 TPS + 0.3s
depth distribution approximated

Methodology

  1. State space. 3x3 = 4.3252 × 10^19 states; 2x2 = 3,674,160; Pyraminx = 933,120; Skewb = 3,149,280. Their full depth distributions are known.
  2. Distribution sources. 3x3: cube20.org / Rokicki 2010 (exact d=0..15, est. d=16..20). 2x2: Korf / Pochmann. Pyraminx / Skewb: Jaap Scherphuis. Larger cubes etc.: peak-concentrated approximation.
  3. Accumulated scrambles N(Y). 2003–2025 from WCA dump (≈28k comps total), 2026+ extrapolated at 5% CAGR capped at 30k comps/year. Per-comp 3x3 scrambles (incl. backups) linearly interpolated 30 → 250 (2003 → 2026). Other events by share factor (4x4 ≈ 0.70 × 3x3).
  4. Cumulative probability. P(hit at least one d ≤ K in N draws) = 1 − (1 − p_le_K)^N, with p_le_K = ∑_{i≤K} counts[i] / |S|. Implemented via log1p(-p) for numerical stability when p is tiny.
  5. Expected min E[min]. E[min depth] = ∑_{k=0}^{G-1} (1 − P(min ≤ k)), then clamped to WCA-acceptable minimum (3x3 ≥ 2; 2x2 / Pyraminx / Skewb ≥ 1).
  6. Execution time. T = E[min] / TPS_ceil + setup_s. TPS_ceil = physiological ceiling (3x3 = 17, dual-hand 22 Hz drum × 50% loss), OH = 10, big cubes 8–12. setup_s = trigger + tap-off 0.10–2.00 s.
  7. Asymptote (N → ∞). 3x3: 2 moves / 17 TPS + 0.15 s = 0.27 s. 2x2 / Pyraminx / Skewb: 1 move / TPS_ceil + setup ≈ 0.16–0.20 s. These are reachable only when luck + TPS are both maxed; the physical floor (M/TPS+R) is still ~1.5 s and bounds real-comp WRs.

Caveats

  • WCA scrambler is uniform sampling, but TNoodle outputs 17–25 move sequences (not filtered for short-solve states). A cumulative hit is mathematical; in practice the cuber would also have to recognize "this is a d=4 state" mid-comp and find a 4-move optimal solution (no algorithm book covers low-d states).
  • Recognition + switching + reaction + dual-hand coordination floor (≥ 50 ms StackMat trigger) mean the "d=2 + 17 TPS" 0.27 s is unreachable; the physical floor is ~1.5 s.
  • Large cubes / Megaminx / Sq1 / Clock distributions not enumerated; peak-concentrated approximation. Order-of-magnitude reliable, not single-digit.
  • FMC / blind not modeled (FMC time = move count; blind is memo-bound, not TPS).
Depth distributions: cube20.org / Rokicki / Korf / Pochmann / Scherphuis · Comp counts: WCA results dump