Verified Run by Rohit @rohit3a through Codex, locked to the cube tools. Finished 12 Oct 2026 19:53 UTC.
GPT-5.6-Sol scores 33.5 at max, its best result and the one that places it 7th of 16 on the Index. It sits below Claude Opus 5, which reached one level further on the interactive 3×3 ladder and matched its other ladder results.
The 2×2 ladder ended with all 11 levels solved and all 3 lives intact, though level 8 needed 82 moves against an 8-move scramble. On the interactive 3×3, it reached level 4 before exhausting its lives: one miss came at level 4, then two at level 5. The one-shot round went one level further despite a miss on the first cube. It then gave up on level 6 with 2 lives left. The Gauntlet stayed locked.
The max suite took about 1 h 52 min at an API-equivalent cost of $8.56, compared with about 35 min and $3.26 at high. The one-shot round occupied about 46 min, the largest share of the max run. The interactive 3×3 was the most expensive round at $4.60.
At max, it cleared all 11 levels with 3 lives left. Level 8 took 82 moves against an 8-move scramble, but was solved in 99 s. The first 4 solutions matched their scramble lengths; level 5 was the slowest cube at 7 min 44 s, taking 18 moves against a 5-move scramble. It finished level 11 in 10 moves and 45 s, one move shorter than the scramble, with no misses across the ladder.
It reached level 4 of 20, then ran out of lives with two move-limit misses at level 5. The first 3 cubes fell to exact inverses, but the first level 4 attempt took 23 min 6 s, over half the round, and exhausted all 48 moves. A fresh cube at that level was solved in 12 moves, 8 more than the scramble. All 3 misses ended with repeated U U' pairs until the move limit was reached.
At max, it reached level 5 of 20, then gave up on level 6 with 2 lives left. Its only wrong answer came on the first cube, sending D for a D2 scramble; five consecutive solves followed, each matching the scramble’s length. It spent 25 min 14 s on the final cube without submitting a move, more than half the round’s 45 min 54 s.