TRACE · ROUND 4

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

claude-opus-5 · 20260724-opus5-twister · round 4 back to model →
events
43
tool calls
35
rejected
1
session
0:00
Session trace

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

  2. ToolSearch
    {"max_results":15,"query":"select:mcp__coaster__new_ride,mcp__coaster__place_piece,mcp__coaster__place_pieces,mcp__coaster__valid_next_pieces,mcp__coaster__piece_geometry,mcp__coaster__get_state,mcp__coaster__finish_and_test,mcp__coaster__best_result,mcp__coaster__undo_piece,mcp__coaster__demolish,mcp__coaster__screenshot"}
  3. Bashrejected
    {"command":"ls /home/sandbox/.claude/projects/-workspace/memory/ 2>/dev/null && cat /home/sandbox/.claude/projects/-workspace/memory/MEMORY.md 2>/dev/null","description":"Check memory directory"}
    Exit code 1
  4. 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)

  5. Loading tools done. Previous round: 7.06 excitement, intensity 9.91 (nearly capped), lateral G 3.04. Plan: fully-banked turns, more airtime, keep intensity headroom.

  6. 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}
  7. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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_to_flat"}]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":54,"y":77,"z":320},"placed_this_call":19,"total_placed":19}
  8. place_pieces
    {"pieces":["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"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":53,"y":87,"z":112},"placed_this_call":9,"total_placed":28}
  9. place_pieces
    {"pieces":["flat_to_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_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":3,"slope":0,"x":55,"y":77,"z":112},"placed_this_call":12,"total_placed":40}
  10. place_pieces
    {"pieces":["flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","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","brakes","brakes","flat","flat","right_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":16,"total_placed":56}

  11. Circuit closed on the first attempt. Banking a score:

  12. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":90,"max_z":344,"min_tile_x":53,"min_tile_y":60,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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_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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_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","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat","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","brakes","brakes","flat","flat","right_tur… (1875 chars)

  13. Excitement 6.10 banked, but intensity is only 6.07 — lots of headroom. Rebuilding much bigger: taller lift, two loops, corkscrews, big airtime hills.

  14. demolish
    {"demolished":0}
  15. 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}
  16. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":53,"y":91,"z":112},"placed_this_call":32,"total_placed":32}
  17. place_pieces
    {"pieces":["flat_to_left_bank","banked_left_turn_3","banked_left_turn_3","left_bank_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","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","right_corkscrew_up","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":46,"y":69,"z":112},"placed_this_call":23,"total_placed":55}
  18. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","flat","flat","brakes","brakes","brakes","brakes","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","left_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":29,"total_placed":84}
  19. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":93,"max_z":376,"min_tile_x":46,"min_tile_y":54,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_3","banked_left_turn_3","left_bank_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","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","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_… (2250 chars)

  20. Solid gain. Now adding a mid-ride second chain lift + second big drop (the round-3 trick that gave high average speed) plus 4 inversions.

  21. demolish
    {"demolished":0}
  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","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_3","banked_left_turn_3","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":47,"y":87,"z":112},"placed_this_call":38,"total_placed":38}
  24. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_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,"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_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","right_corkscrew_up","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":45,"y":48,"z":112},"placed_this_call":37,"total_placed":75}
  25. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat","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","up_25_to_flat","flat_to_down_25","down_25_to_flat","brakes","brakes","flat","flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","flat","flat","flat","flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","left_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":43,"total_placed":118}
  26. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":93,"max_z":376,"min_tile_x":45,"min_tile_y":33,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_3","banked_left_turn_3","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"… (2930 chars)

  27. 6.94 — close. Lateral G (3.01) is eating intensity budget. Swapping the fast 3-tile turns for wider 5-tile ones and adding a 5th inversion.

  28. demolish
    {"demolished":0}
  29. 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}
  30. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","right_corkscrew_up","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":42,"y":84,"z":112},"placed_this_call":40,"total_placed":40}
  31. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_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,"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_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","right_corkscrew_up","left_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":40,"y":45,"z":112},"placed_this_call":37,"total_placed":77}
  32. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat","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","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","flat","flat","flat","flat","flat","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","brakes","brakes","brakes","brakes","flat","flat","flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","left_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":51,"total_placed":128}
  33. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":94,"max_z":376,"min_tile_x":40,"min_tile_y":30,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true… (3058 chars)

  34. 7.09 — new best, beats last round. One more iteration with extra airtime hops in the flat sections:

  35. demolish
    {"demolished":0}
  36. 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}
  37. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"chain":true,"piece":"flat_to_up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"piece":"up_25"},{"chain":true,"p… (1730 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":40,"y":45,"z":112},"placed_this_call":77,"total_placed":77}
  38. place_pieces
    {"pieces":["flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat","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","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","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_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","brakes","brakes","brakes","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","left_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":51,"total_placed":128}
  39. finish_and_test
    {"bounds":{"max_tile_x":63,"max_tile_y":94,"max_z":376,"min_tile_x":40,"min_tile_y":30,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true… (3138 chars)
  40. best_result
    {"bounds":{"max_tile_x":63,"max_tile_y":94,"max_z":376,"min_tile_x":40,"min_tile_y":30,"min_z":112},"placed_pieces":["begin_station","middle_station","middle_station","end_station","right_turn_5",{"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"},{"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","flat_to_left_bank","banked_left_turn_5","banked_left_turn_5","left_bank_to_flat","right_corkscrew_up","left_corkscrew_down","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true… (3138 chars)
  41. Write
    {"content":"---\nname: rct2-coaster-contest-tactics\ndescription: What actually moves excitement in the RCT2 steel-twister (ride_type 51) building contest\nmetadata:\n  type: project\n---\n\nMulti-round RCT2 coaster contest via the `coaster` MCP tools. Measured results across rounds 3-4 (best so far: 7.13 excitement, 128 pieces):\n\n- A **second mid-ride chain lift** is the single biggest lever. Draining all height into one drop leaves the back half slow; re-lifting to ~320z mid-circuit doubled `num_drops` (7 -> 14) and pushed `average_speed` from ~148k to ~232k. Excitement went 6.60 -> 7.13.\n- **Airtime hops are cheap excitement.** Swapping plain `flat` runs for `flat_to_up_25, up_25_to_flat, flat_to_down_25, down_25_to_flat` (same footprint, net dz 0) took `total_air_time` 64 -> 84.\n- Inversions count per *element*, not per piece: a `corkscrew_up`+`corkscrew_down` pair = 1 inversion, same as one vertical loop.\n- Intensity is the binding constraint, not excitement. It sat at 9.4-10.2 in every good build. `max_positive_g` ~4.7 comes from the vertical loops and 60-degree pullouts and did NOT respond to swapping `banked_*_turn_3` for `banked_*_turn_5` (lateral G stayed 2.99).\n- S… (1736 chars)
    File created successfully at: /home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-contest-tactics.md
  42. Write
    {"content":"- [RCT2 coaster contest tactics](rct2-coaster-contest-tactics.md) — mid-ride second chain lift is the biggest excitement lever; intensity is the binding constraint.\n","file_path":"/home/sandbox/.claude/projects/-workspace/memory/MEMORY.md"}
    File created successfully at: /home/sandbox/.claude/projects/-workspace/memory/MEMORY.md (file state is current in your context — no need to Read it back)

  43. Round 4 progression, all tested and banked: | Build | Excitement | Intensity | Length | Drops | Inversions | Airtime | |---|---|---|---|---|---|---| | v1 (single lift, 56 pcs) | 6.10 | 6.07 | 401 | 5 | 2 | 22 | | v2 (bigger hills, 84 pcs) | 6.60 | 8.74 | 557 | 7 | 3 | 40 | | v3 (+ mid-ride lift, 118 pcs) | 6.94 | 9.37 | 770 | 10 | 4 | 52 | | v4 (+ 5th inversion, 128 pcs) | 7.09 | 9.88 | 851 | 12 | 5 | 64 | | **v5 (+ airtime hops)** | **7.13** | 10.17 | 853 | 14 | 5 | 84 | The decisive change was a **second chain lift mid-circuit**: the first version dumped all its height into one drop and crawled through the back half (avg speed 148k). Re-lifting to 320z halfway restored speed to 232k and doubled the drop count. Swapping flat straights for bunny-hops then added 20 units of airtime for free. Two caveats worth stating plainly: the winning build's intensity is **10.17, just over the ~10 guideline** — it still scored highest, so the penalty appears soft rather than a cliff, but I didn't have budget left to confirm whether a sub-10 variant would score better. I also tried widening the fast turns (3-tile → 5-tile) specifically to cut lateral G; it did nothing, lateral G stayed at 2.99, so that G is coming from the loops/corkscrews themselves, not the turns. Best coaster: a 128-piece dual-lift twister — 240-unit plunge into a vertical loop, two corkscrew pairs, a mid-ride re-lift into a second 208-unit drop with a second loop and corkscrew, then a bunny-hop run home — **7.13 excitement** (similarity 0.39, well under the 0.5 penalty).

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