RUN 20260725-opus5-opennote (design + open note)

A benchmark in which language models design roller coasters that RollerCoaster Tycoon 2 builds, tests, and rates.

Standings

design mode — models build from scratch

modelscoreintensitynausea similaritybesttokens / cost
1st claude-opus-5 7.39 9.18 4.88 0.38 round 6/6 286 in / 200k out · $7.91

score = excitement, scaled down when similarity to a stock library design exceeds 0.5 (an exact or mirrored copy scores 0)

claude-opus-5full detail →
excitementintensity×build failed
0515intensity ceiling 10excitementintensityR1R2R3R4R5R6

Round 1 trace (42) →

excitement6.94 intensity7.94 nausea4.49
length 660 m drops 14 airtime 89 tested ok similarity 0.47 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_downbrakesbrakes
98 pieces · 15 on the lift · 9 inversions
track program (98 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "brakes",
    "brakes",
    "flat",
    "flat",
    "flat",
    "left_turn_5",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "left_turn_5"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 1

Round 2 trace (35) →

excitement7.09 intensity8.60 nausea4.77
length 673 m drops 14 airtime 100 tested ok similarity 0.39 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_downbrakesbrakes
98 pieces · 15 on the lift · 9 inversions · 16 added, 16 removed vs the round before (82 of 98 pieces kept)
track program (98 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "brakes",
    "brakes",
    "flat",
    "flat",
    "flat",
    "left_turn_5",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "left_turn_5"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 2

Round 3 trace (31) →

excitement7.12 intensity9.08 nausea4.79
length 828 m drops 14 airtime 100 tested ok similarity 0.34 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_down
104 pieces · 15 on the lift · 9 inversions · 12 added, 6 removed vs the round before (92 of 98 pieces kept)
track program (104 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "right_turn_5",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "left_turn_5",
    "left_turn_5",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "left_turn_5"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 3

Round 4 trace (25) →

excitement7.12 intensity9.08 nausea4.79
length 828 m drops 14 airtime 100 tested ok similarity 0.34 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_down
104 pieces · 15 on the lift · 9 inversions · identical to the round before
track program (104 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "right_turn_5",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "left_turn_5",
    "left_turn_5",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "left_turn_5"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 4

Round 5 trace (49) →

excitement7.12 intensity9.08 nausea4.79
length 828 m drops 14 airtime 100 tested ok similarity 0.34 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_down
104 pieces · 15 on the lift · 9 inversions · identical to the round before
track program (104 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "right_turn_5",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "left_turn_5",
    "left_turn_5",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "s_bend_right",
    "s_bend_left",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "left_turn_5"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 5

Round 6 trace (42) →

excitement7.39 intensity9.18 nausea4.88
length 744 m drops 15 airtime 116 tested ok similarity 0.38 (nearest: Driftwood)
left_vertical_loopleft_corkscrew_upleft_corkscrew_downright_vertical_loopright_corkscrew_upright_corkscrew_downleft_vertical_loopleft_corkscrew_upleft_corkscrew_down
107 pieces · 15 on the lift · 9 inversions · 16 added, 13 removed vs the round before (91 of 104 pieces kept)
track program (107 pieces)
{
  "pieces": [
    "begin_station",
    "middle_station",
    "middle_station",
    "end_station",
    {
      "chain": true,
      "t": "flat_to_up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25"
    },
    {
      "chain": true,
      "t": "up_25_to_flat"
    },
    "flat_to_down_25",
    "down_25_to_down_60",
    "down_60",
    "down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25",
    "up_25",
    "up_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_flat",
    "flat_to_up_25",
    "right_vertical_loop",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "right_corkscrew_up",
    "right_corkscrew_down",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "left_vertical_loop",
    "down_25_to_flat",
    "left_corkscrew_up",
    "left_corkscrew_down",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_up_60",
    "up_60_to_flat",
    "flat_to_down_60",
    "down_60_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25_to_flat",
    "left_turn_5",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_up_25",
    "up_25_to_flat",
    "flat_to_down_25",
    "down_25",
    "down_25_to_flat",
    "flat_to_right_bank",
    "banked_right_turn_3",
    "right_bank_to_flat",
    "s_bend_right",
    "right_turn_5",
    "right_turn_5",
    "flat",
    "flat",
    "flat"
  ],
  "ride_type": 51,
  "start": {
    "dir": 0,
    "x": 60,
    "y": 60
  }
}
park screenshot, claude-opus-5 round 6

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