Bracket second mount
hard tier · iterate
The requests, in order
1Make an L-bracket, lying in the XY plane with Z up. A base plate 50 mm along X by 40 mm along Y by 4 mm thick, centred on the origin in X and Y with its bottom face on Z = 0, plus an upright wall 50 mm wide, 40 mm tall and 4 mm thick standing on the base's +Y edge, so the bracket's overall height is 40 mm, with the wall running from Z = 0 to Z = 40, its outer face at Y = 20 and its inner face at Y = 16. Put two 4.4 mm holes through the base at X = ±15, Y = −10. Name the sub-part exactly `bracket`.
2Add two more 4.4 mm holes, this time straight through the upright wall along Y, at X = ±15 and Z = 30. Keep the base holes exactly where they are.
3Lighten the upright with one 20 mm diameter hole through it, centred at X = 0 and Z = 20, without touching any of the four existing holes.
What the AI judge checks
- An L-shaped bracket: a flat base plate with a wall standing up along one edge
- Two small round holes through the flat base plate
- Two small round holes through the upright wall, near its top
- One much larger round hole through the middle of the upright wall
- The large hole does not run into or overlap any of the small holes
Measured checks
- one sub-part named bracket (gate)
- base hole at X = 15 is 4.4 mm (gate)
- base hole at X = -15 is 4.4 mm (gate)
- one sub-part named bracket (gate)
- base hole at X = 15 is 4.4 mm (gate)
- base hole at X = -15 is 4.4 mm (gate)
- upright hole at X = 15, Z = 30 is clear (gate)
- upright hole at X = -15, Z = 30 is clear (gate)
- one sub-part named bracket (gate)
- base hole at X = 15 is 4.4 mm (gate)
- base hole at X = -15 is 4.4 mm (gate)
- upright hole at X = 15, Z = 30 is clear (gate)
- upright hole at X = -15, Z = 30 is clear (gate)
- 20 mm lightening hole is clear
- material remains just outside the 20 mm hole
Ranked by hand
One reviewer put one attempt from each model in order, best first, ties left tied.
- #1 tieGemini 3.8 Flash

- #1 tieHaiku 5.5

- #1 tieGPT-6 Sol

- #1 tieGPT-6.1 Sol

- #1 tieSonnet 5.5

- #1 tieGemini 4 Argon

- #1 tieOpus 5.5

Ordering by hand decides Human rank and Human rate on the leaderboard; it never affects Overall or Strict.
Every model's attempts
Run hard-compact-2026-10-162026-10-16commit 6fa9f854spend $116.04 + $54.69 AI judging, 1 unpricedOther runs: 2026-09-23T06-56-16-hard-baseline-2026-09-23, 2026-09-10T19-44-23-baseline-2026-09, 2026-09-04T20-02-10-stage2-hard-cases, 2026-09-04T19-48-31-screen-14-fixed