TRACE · ROUND 3

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

claude-opus-5 · 20260724-opus5-twister · round 3 back to model →
events
27
tool calls
22
rejected
0
session
0:00
Session trace

  1. I'll start by loading the coaster tools.

  2. ToolSearch
    {"max_results":15,"query":"coaster ride track piece"}
  3. piece_geometry
    {"dir":0}
    {"deltas":[{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":0,"piece":"flat","slope_out":0},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":0,"piece":"end_station","slope_out":0},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":0,"piece":"begin_station","slope_out":0},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":0,"piece":"middle_station","slope_out":0},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":16,"piece":"up_25","slope_out":2},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":64,"piece":"up_60","slope_out":4},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":8,"piece":"flat_to_up_25","slope_out":2},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":32,"piece":"up_25_to_up_60","slope_out":4},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":32,"piece":"up_60_to_up_25","slope_out":2},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":8,"piece":"up_25_to_flat","slope_out":0},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":-16,"piece":"down_25","slope_out":6},{"bank_out":0,"dir_out":0,"dx_tiles":-1,"dy_tiles":0,"dz":-64,"piece":"down_60","slope_out":8},{"bank_out":0,"dir_out":0,"dx… (7397 chars)
  4. new_ride
    {"dir":0,"ride_type":51,"x":60,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"ride_id":0}
  5. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"left_turn_5_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25_to_flat"}]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":45,"y":52,"z":384},"placed_this_call":19,"total_placed":19}
  6. place_pieces
    {"pieces":["flat_to_down_25","down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":48,"y":32,"z":144},"placed_this_call":23,"total_placed":42}
  7. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","flat_to_up_25","right_vertical_loop","down_25_to_flat","left_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_right_bank","banked_right_turn_5","right_bank_to_flat"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":50,"y":54,"z":144},"placed_this_call":20,"total_placed":62}
  8. place_pieces
    {"pieces":["left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25_to_flat","brakes","brakes","flat_to_left_bank","banked_left_turn_3","banked_left_turn_3","left_bank_to_flat"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":14,"total_placed":76}
  9. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":60,"max_z":408,"min_tile_x":43,"min_tile_y":28,"min_z":112},"placed_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":"left_turn_5_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","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_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","right_vertical_loop","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","… (2234 chars)

  10. Banked 6.73. Now let me try a much longer two-lift design.

  11. new_ride
    {"dir":0,"ride_type":51,"x":60,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"ride_id":0}
  12. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"left_turn_5_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25_to_flat"},"flat_to_down_25","down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":50,"y":30,"z":112},"placed_this_call":46,"total_placed":46}
  13. place_pieces
    {"pieces":[{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25_to_flat"},"flat_to_down_25","down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25","down_25","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","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":54,"y":68,"z":112},"placed_this_call":36,"total_placed":82}
  14. place_pieces
    {"pieces":["flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","flat_to_right_bank","banked_right_turn_3","right_bank_to_flat","brakes","brakes","flat","flat","flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":18,"total_placed":100}
  15. finish_and_test
    {"bounds":{"max_tile_x":64,"max_tile_y":71,"max_z":376,"min_tile_x":41,"min_tile_y":26,"min_z":112},"placed_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":"left_turn_5_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","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"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… (2724 chars)

  16. Excitement 7.06 banked. Now extending with more airtime and inversions.

  17. new_ride
    {"dir":0,"ride_type":51,"x":60,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"ride_id":0}
  18. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"left_turn_5_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25_to_flat"},"flat_to_down_25","down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piec… (1792 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":54,"y":68,"z":112},"placed_this_call":82,"total_placed":82}
  19. place_pieces
    {"pieces":["flat_to_up_60","up_60_to_flat","flat_to_down_60","down_60_to_flat","flat_to_up_60","up_60_to_flat","flat_to_down_60","down_60_to_flat","flat_to_up_60","up_60_to_flat","flat_to_down_60","down_60_to_flat","flat_to_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_up_60","up_60_to_flat","flat_to_down_60","down_60_to_flat","flat_to_up_60","up_60_to_flat","flat_to_down_60","down_60_to_flat","right_corkscrew_up","left_corkscrew_down","brakes","brakes","flat","flat_to_left_bank","banked_left_turn_3","left_bank_to_flat","flat","flat","flat_to_right_bank","banked_right_turn_3","banked_right_turn_3","right_bank_to_flat"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":38,"total_placed":120}
  20. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":83,"max_z":376,"min_tile_x":41,"min_tile_y":26,"min_z":112},"placed_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":"left_turn_5_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","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"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… (3109 chars)

  21. Intensity 11.41 tanked it (60° camelbacks → -2.71 G). Swapping them for gentle hills, same footprint.

  22. new_ride
    {"dir":0,"ride_type":51,"x":60,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"ride_id":0}
  23. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"left_turn_5_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25_to_flat"},"flat_to_down_25","down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piec… (1792 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":54,"y":68,"z":112},"placed_this_call":82,"total_placed":82}
  24. place_pieces
    {"pieces":["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","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_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_corkscrew_up","left_corkscrew_down","brakes","brakes","flat","flat_to_left_bank","banked_left_turn_3","left_bank_to_flat","flat","flat","flat_to_right_bank","banked_right_turn_3","banked_right_turn_3","right_bank_to_flat"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":38,"total_placed":120}
  25. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":83,"max_z":376,"min_tile_x":41,"min_tile_y":26,"min_z":112},"placed_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":"left_turn_5_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","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"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… (3127 chars)
  26. best_result
    {"bounds":{"max_tile_x":64,"max_tile_y":71,"max_z":376,"min_tile_x":41,"min_tile_y":26,"min_z":112},"placed_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":"left_turn_5_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","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat",{"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… (2724 chars)

  27. Banked score confirmed: **7.06 excitement**. **Round 3 summary:** Best coaster is a 100-piece dual-lift steel twister — 30 ft chain climb into a 60° plunge, vertical loop, corkscrew, a banked U-turn into a *second* chain lift, a second 26-unit drop into a right vertical loop, a third corkscrew that dives under the first lift hill, and a banked return run to the brakes. **Excitement 7.06, intensity 9.91, nausea 5.97, 5 inversions, 685 ft ride length, similarity 0.36** (no penalty). Learnings this round (tried and measured): pushing to 120 pieces with 6 inversions and 60° camelbacks gave great raw stats (824 length, 15 drops, 98 air time) but drove intensity to 11.41 and excitement collapsed to 5.57; softening the camelbacks to 25° only got intensity to 10.71 (5.46) — the length/turn count alone was over budget. The 100-piece version sits right under the intensity cliff and is the keeper.

← claude-opus-5 · 20260724-opus5-twister · all runs