TRACE · ROUND 6

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

claude-fable-5-1 · 20260902-fable51-design-full · round 6 back to model →
events
52
tool calls
39
rejected
9
session
0:00
Session trace

  1. I'll load the coaster tools, rebuild a proven layout quickly to bank a score, then try to improve on it.

  2. ToolSearch
    {"max_results":12,"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__undo_piece,mcp__coaster__get_state,mcp__coaster__finish_and_test,mcp__coaster__best_result,mcp__coaster__style_best_ride,mcp__coaster__demolish,mcp__coaster__screenshot"}
  3. Read
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-twister-lateral-g-rule.md"}
    1	---
2	name: rct2-twister-lateral-g-rule
3	description: "RCT2 coaster contest - max lateral G above 2.80 adds ~2-4 intensity, above 3.10 halves excitement; corkscrews at full speed are the cause"
4	metadata: 
5	  node_type: memory
6	  type: project
7	  originSessionId: f4c10eb0-30fc-48dc-8f63-4cb72062c90a
8	  modified: 2026-09-02T19:43:03.937Z
9	---
10	
11	In the RCT2 steel twister (ride_type 51) coaster contest, the eval applies the OpenRCT2 excessive-lateral-G penalty: max_lateral_g > 2.80 adds roughly 2-4 intensity; > 3.10 halves excitement and adds ~8 intensity (round 5 v3 test: lateral 3.23 gave excitement 1.62, intensity 15.07).
12	
13	**Why:** Corkscrew pairs placed at ground level right after a booster 25 or vertical loop produce lateral G ~3.2. Putting the corkscrew pair on top of a climb (flat_to_up_25 + 4x up_25 + up_25_to_flat, then right_corkscrew_up / left_corkscrew_down, then 80 units of descent) keeps lateral at 2.78 and adds an inversion safely. Vertical loops at booster 25 add no lateral G.
14	
15	**How to apply:** Best round-5 design (7.19 excitement, intensity 8.67, 6 inversions) starts at (66,60) dir 0, 12-piece chain lift, 60-degree drop, hump then left verti… (1566 chars)
  4. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}

  5. I'll replay the round-5 baseline (123 pieces) in one batch to bank the 7.19 quickly.

  6. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2023 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"placed_this_call":123,"total_placed":123}
  7. finish_and_test
    {"bounds":{"max_tile_x":83,"max_tile_y":60,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (2937 chars)

  8. Score of 7.19 is banked. Now I'll fetch the piece geometry for all four facings so I can compute the layout offline and plan a longer, ground-hugging extension that closes the circuit.

  9. 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)
  10. piece_geometry
    {"dir":1}
    {"deltas":[{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":0,"piece":"flat","slope_out":0},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":0,"piece":"end_station","slope_out":0},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":0,"piece":"begin_station","slope_out":0},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":0,"piece":"middle_station","slope_out":0},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":16,"piece":"up_25","slope_out":2},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":64,"piece":"up_60","slope_out":4},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":8,"piece":"flat_to_up_25","slope_out":2},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":32,"piece":"up_25_to_up_60","slope_out":4},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":32,"piece":"up_60_to_up_25","slope_out":2},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":8,"piece":"up_25_to_flat","slope_out":0},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":-16,"piece":"down_25","slope_out":6},{"bank_out":0,"dir_out":1,"dx_tiles":0,"dy_tiles":1,"dz":-64,"piece":"down_60","slope_out":8},{"bank_out":0,"dir_out":1,"dx_tiles":0,"d… (7346 chars)
  11. piece_geometry
    {"dir":2}
    {"deltas":[{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":0,"piece":"flat","slope_out":0},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":0,"piece":"end_station","slope_out":0},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":0,"piece":"begin_station","slope_out":0},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":0,"piece":"middle_station","slope_out":0},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":16,"piece":"up_25","slope_out":2},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":64,"piece":"up_60","slope_out":4},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":8,"piece":"flat_to_up_25","slope_out":2},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":32,"piece":"up_25_to_up_60","slope_out":4},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":32,"piece":"up_60_to_up_25","slope_out":2},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":8,"piece":"up_25_to_flat","slope_out":0},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":-16,"piece":"down_25","slope_out":6},{"bank_out":0,"dir_out":2,"dx_tiles":1,"dy_tiles":0,"dz":-64,"piece":"down_60","slope_out":8},{"bank_out":0,"dir_out":2,"dx_tiles":1,"d… (7346 chars)
  12. piece_geometry
    {"dir":3}
    {"deltas":[{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":0,"piece":"flat","slope_out":0},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":0,"piece":"end_station","slope_out":0},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":0,"piece":"begin_station","slope_out":0},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":0,"piece":"middle_station","slope_out":0},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":16,"piece":"up_25","slope_out":2},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":64,"piece":"up_60","slope_out":4},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":8,"piece":"flat_to_up_25","slope_out":2},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":32,"piece":"up_25_to_up_60","slope_out":4},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":32,"piece":"up_60_to_up_25","slope_out":2},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":8,"piece":"up_25_to_flat","slope_out":0},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":-16,"piece":"down_25","slope_out":6},{"bank_out":0,"dir_out":3,"dx_tiles":0,"dy_tiles":-1,"dz":-64,"piece":"down_60","slope_out":8},{"bank_out":0,"dir_out":3,"dx… (7397 chars)
  13. Bashrejected
    {"command":"mkdir -p /tmp/rc && cat > /tmp/rc/geo.py <<'EOF'\nimport json\n# dir0 deltas: piece -> (dx,dy,dz,dir_delta,slope_out,bank_out)\nG0 = {\n 'flat':(-1,0,0,0),'begin_station':(-1,0,0,0),'middle_station':(-1,0,0,0),'end_station':(-1,0,0,0),\n 'up_25':(-1,0,16,0),'up_60':(-1,0,64,0),'flat_to_up_25':(-1,0,8,0),'up_25_to_up_60':(-1,0,32,0),'up_60_to_up_25':(-1,0,32,0),'up_25_to_flat':(-1,0,8,0),\n 'down_25':(-1,0,-16,0),'down_60':(-1,0,-64,0),'flat_to_down_25':(-1,0,-8,0),'down_25_to_down_60':(-1,0,-32,0),'down_60_to_down_25':(-1,0,-32,0),'down_25_to_flat':(-1,0,-8,0),\n 'left_turn_5':(-2,-3,0,3),'right_turn_5':(-2,3,0,1),'flat_to_left_bank':(-1,0,0,0),'flat_to_right_bank':(-1,0,0,0),'left_bank_to_flat':(-1,0,0,0),'right_bank_to_flat':(-1,0,0,0),\n 'banked_left_turn_5':(-2,-3,0,3),'banked_right_turn_5':(-2,3,0,1),\n 'left_bank_to_up_25':(-1,0,8,0),'right_bank_to_up_25':(-1,0,8,0),'up_25_to_left_bank':(-1,0,8,0),'up_25_to_right_bank':(-1,0,8,0),\n 'left_bank_to_down_25':(-1,0,-8,0),'right_bank_to_down_25':(-1,0,-8,0),'down_25_to_left_bank':(-1,0,-8,0),'down_25_to_right_bank':(-1,0,-8,0),\n 'left_bank':(-1,0,0,0),'right_bank':(-1,0,0,0),\n 'left_turn_5_up_25':(-2,-3,64,3),'right_… (5455 chars)
    Contains brace with quote character (expansion obfuscation)
  14. Writerejected
    {"content":"import json, sys\n# dir0 deltas: piece -> (dx,dy,dz,dir_delta)\nG0 = {\n 'flat':(-1,0,0,0),'begin_station':(-1,0,0,0),'middle_station':(-1,0,0,0),'end_station':(-1,0,0,0),\n 'up_25':(-1,0,16,0),'up_60':(-1,0,64,0),'flat_to_up_25':(-1,0,8,0),'up_25_to_up_60':(-1,0,32,0),'up_60_to_up_25':(-1,0,32,0),'up_25_to_flat':(-1,0,8,0),\n 'down_25':(-1,0,-16,0),'down_60':(-1,0,-64,0),'flat_to_down_25':(-1,0,-8,0),'down_25_to_down_60':(-1,0,-32,0),'down_60_to_down_25':(-1,0,-32,0),'down_25_to_flat':(-1,0,-8,0),\n 'left_turn_5':(-2,-3,0,3),'right_turn_5':(-2,3,0,1),'flat_to_left_bank':(-1,0,0,0),'flat_to_right_bank':(-1,0,0,0),'left_bank_to_flat':(-1,0,0,0),'right_bank_to_flat':(-1,0,0,0),\n 'banked_left_turn_5':(-2,-3,0,3),'banked_right_turn_5':(-2,3,0,1),\n 'left_bank_to_up_25':(-1,0,8,0),'right_bank_to_up_25':(-1,0,8,0),'up_25_to_left_bank':(-1,0,8,0),'up_25_to_right_bank':(-1,0,8,0),\n 'left_bank_to_down_25':(-1,0,-8,0),'right_bank_to_down_25':(-1,0,-8,0),'down_25_to_left_bank':(-1,0,-8,0),'down_25_to_right_bank':(-1,0,-8,0),\n 'left_bank':(-1,0,0,0),'right_bank':(-1,0,0,0),\n 'left_turn_5_up_25':(-2,-3,64,3),'right_turn_5_up_25':(-2,3,64,1),'left_turn_5_down_25':(-2,-3,-64,3),'r… (3000 chars)
    Claude requested permissions to write to /tmp/rc/geo.py, but you haven't granted it yet.
  15. Writerejected
    {"content":"[\"begin_station\",\"middle_station\",\"end_station\",\"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\"},\"up_25_to_flat\",\"flat_to_down_60\",\"down_60\",\"down_60\",\"down_60_to_down_25\",\"down_25\",\"down_25_to_flat\",\"flat_to_up_25\",\"up_25\",\"up_25_to_flat\",\"flat_to_up_25\",\"left_vertical_loop\",\"down_25_to_flat\",\"flat_to_down_25\",\"down_25\",\"down_25_to_flat\",\"left_corkscrew_up\",\"right_corkscrew_down\",\"flat_to_up_25\",\"up_25\",\"up_25\",\"up_25\",\"up_25\",\"up_25_to_flat\",\"flat_to_left_bank\",\"banked_left_turn_5\",\"left_bank_to_flat\",\"flat_to_down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25_to_flat\",{\"speed\":22,\"t\":\"booster\"},\"flat_to_up_25\",\"half_loop_up\",\"right_corkscrew_down\",\"flat_to_down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25\",\"dow… (2374 chars)
    Claude requested permissions to write to /tmp/rc/base.json, but you haven't granted it yet.
  16. Writerejected
    {"content":"import json, sys\n# dir0 deltas: piece -> (dx,dy,dz,dir_delta)\nG0 = {\n 'flat':(-1,0,0,0),'begin_station':(-1,0,0,0),'middle_station':(-1,0,0,0),'end_station':(-1,0,0,0),\n 'up_25':(-1,0,16,0),'up_60':(-1,0,64,0),'flat_to_up_25':(-1,0,8,0),'up_25_to_up_60':(-1,0,32,0),'up_60_to_up_25':(-1,0,32,0),'up_25_to_flat':(-1,0,8,0),\n 'down_25':(-1,0,-16,0),'down_60':(-1,0,-64,0),'flat_to_down_25':(-1,0,-8,0),'down_25_to_down_60':(-1,0,-32,0),'down_60_to_down_25':(-1,0,-32,0),'down_25_to_flat':(-1,0,-8,0),\n 'left_turn_5':(-2,-3,0,3),'right_turn_5':(-2,3,0,1),'flat_to_left_bank':(-1,0,0,0),'flat_to_right_bank':(-1,0,0,0),'left_bank_to_flat':(-1,0,0,0),'right_bank_to_flat':(-1,0,0,0),\n 'banked_left_turn_5':(-2,-3,0,3),'banked_right_turn_5':(-2,3,0,1),\n 'left_bank_to_up_25':(-1,0,8,0),'right_bank_to_up_25':(-1,0,8,0),'up_25_to_left_bank':(-1,0,8,0),'up_25_to_right_bank':(-1,0,8,0),\n 'left_bank_to_down_25':(-1,0,-8,0),'right_bank_to_down_25':(-1,0,-8,0),'down_25_to_left_bank':(-1,0,-8,0),'down_25_to_right_bank':(-1,0,-8,0),\n 'left_bank':(-1,0,0,0),'right_bank':(-1,0,0,0),\n 'left_turn_5_up_25':(-2,-3,64,3),'right_turn_5_up_25':(-2,3,64,1),'left_turn_5_down_25':(-2,-3,-64,3),'r… (3006 chars)
    Claude requested permissions to write to /workspace/rc/geo.py, but you haven't granted it yet.
  17. Writerejected
    {"content":"[\"begin_station\",\"middle_station\",\"end_station\",\"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\"},\"up_25_to_flat\",\"flat_to_down_60\",\"down_60\",\"down_60\",\"down_60_to_down_25\",\"down_25\",\"down_25_to_flat\",\"flat_to_up_25\",\"up_25\",\"up_25_to_flat\",\"flat_to_up_25\",\"left_vertical_loop\",\"down_25_to_flat\",\"flat_to_down_25\",\"down_25\",\"down_25_to_flat\",\"left_corkscrew_up\",\"right_corkscrew_down\",\"flat_to_up_25\",\"up_25\",\"up_25\",\"up_25\",\"up_25\",\"up_25_to_flat\",\"flat_to_left_bank\",\"banked_left_turn_5\",\"left_bank_to_flat\",\"flat_to_down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25_to_flat\",{\"speed\":22,\"t\":\"booster\"},\"flat_to_up_25\",\"half_loop_up\",\"right_corkscrew_down\",\"flat_to_down_25\",\"down_25\",\"down_25\",\"down_25\",\"down_25\",\"dow… (2380 chars)
    Claude requested permissions to write to /workspace/rc/base.json, but you haven't granted it yet.

  18. With the baseline banked at 7.19, I've traced the return leg's flat run and found open space to its west that I'll use to add a ground-level meander for extra length, duration, and turns without affecting G-forces.

  19. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}
  20. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2281 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"placed_this_call":151,"total_placed":151}

  21. The meander closed the circuit on the first try. Testing it now.

  22. finish_and_test
    {"bounds":{"max_tile_x":83,"max_tile_y":60,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (3195 chars)

  23. Excitement rose to 7.40 (intensity steady at 8.67, similarity dropped to 0.34). I'll remove the last four closing pieces, then extend the ground track along y=59 and y=62 north of the meander, closing into the station with a right turn.

  24. undo_piecerejected
    ride already finalized; use demolish + new_ride to rebuild
  25. undo_piecerejected
    ride already finalized; use demolish + new_ride to rebuild
  26. undo_piecerejected
    ride already finalized; use demolish + new_ride to rebuild
  27. undo_piecerejected
    ride already finalized; use demolish + new_ride to rebuild
  28. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}
  29. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2573 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":3,"slope":0,"x":67,"y":60,"z":112},"placed_this_call":180,"rejection":{"error":"ride type 51 has no artwork for this piece: it would build and rate but render as nothing (invisible track). valid_next_pieces lists what this ride can draw here","index":180,"piece":"right_turn_1"},"total_placed":180}

  30. The tight one-tile turn isn't drawable for this ride type. I'll shift the last east pass to y=63 so two medium right turns land exactly on the station entry, then rebuild.

  31. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}
  32. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2587 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"placed_this_call":183,"total_placed":183}
  33. finish_and_test
    {"bounds":{"max_tile_x":83,"max_tile_y":64,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (3503 chars)

  34. Excitement is banked at 7.57. I'll add a third ground track loop north of the station (y=66/70) closing at x=68, building it in two batches since it exceeds 200 pieces.

  35. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}
  36. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2543 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":65,"y":63,"z":112},"placed_this_call":179,"total_placed":179}

  37. Cursor is at (65,63) facing east as planned. Placing the northern loop and the closing south leg now.

  38. place_pieces
    {"pieces":["left_turn_3","left_turn_3","flat","flat","s_bend_left","s_bend_right","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","flat","right_turn_3","flat","right_turn_3","flat","flat","flat","s_bend_right","s_bend_left","flat","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","flat","right_turn_3","flat","flat","flat","flat","flat","flat","flat","right_turn_3"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"placed_this_call":40,"total_placed":219}
  39. finish_and_test
    {"bounds":{"max_tile_x":83,"max_tile_y":70,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (3831 chars)

  40. Score is now 7.75 with intensity still 8.68. There's time for one more northern pass (y=73 and y=77), so I'll rebuild with that added.

  41. new_ride
    {"dir":0,"ride_type":51,"x":66,"y":60}
    {"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"ride_id":0}
  42. place_pieces
    {"pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_vertical_loop","down_25_to_flat","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","right_cor… (2543 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":65,"y":63,"z":112},"placed_this_call":179,"total_placed":179}
  43. place_pieces
    {"pieces":["left_turn_3","left_turn_3","flat","flat","s_bend_left","s_bend_right","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","flat","right_turn_3","flat","right_turn_3","flat","flat","flat","s_bend_right","s_bend_left","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","left_turn_3","left_turn_3","flat","flat","s_bend_left","s_bend_right","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","flat","right_turn_3","flat","right_turn_3","flat","flat","flat","s_bend_right","s_bend_left","flat","flat","flat",{"speed":13,"t":"booster"},"flat","flat","flat","flat","flat","right_turn_3","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","right_turn_3"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":66,"y":60,"z":112},"placed_this_call":76,"total_placed":255}
  44. finish_and_test
    {"bounds":{"max_tile_x":83,"max_tile_y":77,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (4209 chars)

  45. Excitement is now 7.91 and banked. Finalizing: I'll confirm the best result, name and colour the winner, and record the lesson in memory, all at once.

  46. best_result
    {"bounds":{"max_tile_x":83,"max_tile_y":77,"max_z":344,"min_tile_x":21,"min_tile_y":41,"min_z":112},"placed_pieces":["begin_station","middle_station","end_station","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"},"up_25_to_flat","flat_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_down_25","down_25","down_25_to_flat","left_corkscrew_up","right_corkscrew_down","flat_to_up_25","up_25","up_25","up_25","up_25","up_25_to_flat","flat_to_left_bank","banked_left_turn_5","left_bank_to_flat","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":22,"t":"booster"},"flat_to_up_25","half_loop_up","right_corkscrew_down","flat_to_down_25","down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"booster"},"flat_to_up_25","right_v… (4209 chars)
  47. style_best_ride
    {"name":"Lakeside Serpent","rail_color":"bright_yellow","support_color":"grey","track_color":"dark_blue"}
    {"presentation":{"name":"Lakeside Serpent","rail_color":"bright_yellow","support_color":"grey","track_color":"dark_blue"},"score":7.909999847412109,"score_changed":false,"styled":"best_result"}
  48. Write
    {"content":"---\nname: rct2-ground-meander-lever\ndescription: \"RCT2 coaster contest - flat ground-level meander passes (~40 tiles each) on the return leg add ~+0.17 excitement apiece with zero intensity change; final round-6 result 7.91\"\nmetadata:\n  type: project\n---\n\nIn the RCT2 steel twister (ride_type 51) contest, appending ground-level meander passes to the return leg (brakes 14, then flats + s_bends + turn_3 U-turns, booster 13 every ~10 tiles) raised excitement 7.19 -> 7.40 -> 7.57 -> 7.75 -> 7.91 across four passes while intensity stayed 8.67-8.69 and lateral G stayed 2.78. Ride length went 855 -> 1701 m, ride time 64 -> 120 s, similarity dropped to 0.24.\n\n**Why:** OpenRCT2 ratings add excitement for length (cap 6000 m), duration (cap 150 s), ground-proximity (surface touch) and turn counts; these are independent of G-forces, so they are free intensity-wise. Average speed even rose slightly because the boosters kept the train at 13.\n\n**How to apply:** Build the proven inversion core first (see [[rct2-twister-lateral-g-rule]]), then fill empty ground west/north of the station with 3-tile-spaced passes. Twister has no right_turn_1/left_turn_1 artwork; close into th… (1664 chars)
    File created successfully at: /home/sandbox/.claude/projects/-workspace/memory/rct2-ground-meander-lever.md

  49. The winner is banked at 7.91 and styled. Last step: add the new memory to the index.

  50. Read
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/MEMORY.md"}
    1	- [RCT2 twister lateral-G rule](rct2-twister-lateral-g-rule.md) — keep max lateral G ≤ 2.80; elevate corkscrews; best round-5 layout recipe (7.19)
2
  51. Edit
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/MEMORY.md","new_string":"best round-5 layout recipe (7.19)\n- [RCT2 ground meander lever](rct2-ground-meander-lever.md) — flat ground passes on the return leg add ~+0.17 excitement each at zero intensity; round-6 winner 7.91\n","old_string":"best round-5 layout recipe (7.19)\n","replace_all":false}
    The file /home/sandbox/.claude/projects/-workspace/memory/MEMORY.md has been updated successfully. (file state is current in your context — no need to Read it back)

  52. Nothing further is needed. The round is complete and the winner is banked and styled. **Result:** the best coaster this round is "Lakeside Serpent", a steel twister scoring 7.91 excitement, up from the round-5 baseline of 7.19. | Metric | Round 5 | Final | |---|---|---| | Excitement | 7.19 | 7.91 | | Intensity | 8.67 | 8.69 | | Nausea | 4.51 | 4.63 | | Ride length (m) | 855 | 1701 | | Ride time (s) | 64 | 120 | | Similarity to stock | 0.41 | 0.24 | **What changed.** The inversion core stayed identical: a 12-piece chain lift, 60-degree drop, three vertical loops, a half loop, two elevated corkscrew pairs, and boosters. I replaced the short flat run into the station with four ground-level meander passes west and north of the station, using medium turns, S-bends, and boosters set to 13 to hold speed. Each pass added roughly 0.17 excitement with no change to G-forces or intensity, because the rating formula rewards length, duration, turns and ground proximity independently of G-forces. **Notes for the record.** The one-tile turn has no artwork for this ride type, so the closing into the station uses two medium right turns from a leg three tiles north. Track along x=68 beside the lake was buildable up to y=75. Undo is refused once a ride has been tested, so each iteration was a full replay from new_ride. I saved these lessons in memory alongside the earlier lateral-G rule. Best coaster: "Lakeside Serpent" (dark blue track, bright yellow rails, grey supports), excitement 7.91, intensity 8.69, six inversions, no crash.

← claude-fable-5-1 · 20260902-fable51-design-full · all runs