TRACE · ROUND 6

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

claude-opus-5 · 20260724-opus5-twister · round 6 back to model →
events
44
tool calls
30
rejected
1
session
0:00
Session trace

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

  2. ToolSearch
    {"max_results":15,"query":"coaster new_ride place_piece finish_and_test"}
  3. Read
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-contest-tactics.md"}
    1	---
2	name: rct2-coaster-contest-tactics
3	description: What actually moves excitement in the RCT2 steel-twister (ride_type 51) building contest
4	metadata: 
5	  node_type: memory
6	  type: project
7	  originSessionId: 9566f1cd-bad2-469e-b14f-fe34a6cccace
8	  modified: 2026-07-24T19:24:24.934Z
9	---
10	
11	Multi-round RCT2 coaster contest via the `coaster` MCP tools. Measured results, rounds 3-5.
12	
13	**Scoreboard so far: 7.13 @ intensity 10.17 (round 4) is still the all-time best. Round 5 topped out at 6.94 @ intensity 8.19.**
14	
15	Round-5 measurements, all on one 125-piece layout where only the hill/drop profile changed:
16	
17	| build | drop1 | drop2 | inversions | air | excitement | intensity |
18	|---|---|---|---|---|---|---|
19	| v1 | 192 | 208 | 4 | 64 | 6.74 | 7.42 |
20	| v2 | 240 (2x down_60) | 208 | 5 | 105 | **5.22** | **10.49** |
21	| v3 | 192 | 192 | 5 | 95 | 6.88 | 8.02 |
22	| v4 | 208 | 208 | 5 | 94 | **6.94** | 8.19 |
23	| v5 | 208 | 208 | 6 | 74 | 6.93 | 8.55 |
24	
25	- **Two consecutive `down_60` pieces in one drop is the intensity bomb**: +2.3 intensity (8.19 -> 10.49) for only +4 `highest_drop`. Never chain two. One `down_60` with a 3-piece 25-degree pullo… (2919 chars)
  4. best_resultrejected
    no rated test yet this round

  5. Memory has a detailed playbook from prior rounds. Let me pull geometry and start.

  6. 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)

  7. Memory gives me a proven skeleton. Let me plan a fresh layout with more inversions (targeting intensity ~10.1, the measured sweet spot) and build it.

  8. 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}
  9. 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":"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_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":28,"y":78,"z":112},"placed_this_call":48,"total_placed":48}

  10. Exactly on plan. Continuing with the second lift, drop, and inversion cluster.

  11. 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_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_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","flat_to_up_25","right_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","left_corkscrew_up","right_corkscrew_down"]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":42,"y":103,"z":112},"placed_this_call":33,"total_placed":81}

  12. Cursor matches my paper plan exactly. Now the return leg to close the circuit.

  13. 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","right_bank_to_flat","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","brakes","brakes","brakes","right_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":33,"total_placed":114}

  14. Circuit closed first try. Banking a score now.

  15. finish_and_test
    {"bounds":{"max_tile_x":64,"max_tile_y":104,"max_z":344,"min_tile_x":25,"min_tile_y":59,"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":"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_to_down_25","down_25","down_25","down_25","down_25_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain… (3009 chars)

  16. Banked **7.07** (beats last round's 6.94). Intensity is 8.08 — memory says the sweet spot is ~10.1, so I have headroom. Let me add helices to push lateral G up.

  17. demolish
    {"demolished":0}
  18. 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}
  19. 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":"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_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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","right_helix_up_large","right_helix_down_large","right_bank_to_flat","flat","flat"]}
    {"circuit_closed":false,"cursor":{"bank":4,"dir":3,"slope":0,"x":33,"y":74,"z":128},"placed_this_call":46,"rejection":{"error":"Twister Roller Coaster 1 in the way","index":46,"piece":"right_helix_down_large"},"total_placed":46}

  20. Helix-up-then-down collides (retraces its own footprint). Two up-halves spiral properly instead — I'll climb 32 here and give it back with a descending helix later.

  21. place_pieces
    {"pieces":["right_helix_up_large","right_bank_to_flat","flat","flat"]}
    {"circuit_closed":false,"cursor":{"bank":4,"dir":3,"slope":0,"x":33,"y":74,"z":128},"placed_this_call":0,"rejection":{"error":"Twister Roller Coaster 1 in the way","index":0,"piece":"right_helix_up_large"},"total_placed":46}
  22. valid_next_pieces
    {"cursor":{"bank":4,"dir":3,"slope":0,"x":33,"y":74,"z":128},"valid_pieces":["right_bank_to_flat","banked_right_turn_5","right_bank_to_up_25","right_bank_to_down_25","right_bank","banked_right_turn_3","right_helix_up_small","right_helix_down_small"]}
  23. undo_piece
    {"cursor":{"bank":4,"dir":1,"slope":0,"x":28,"y":75,"z":112},"pieces_placed":45,"removed":"right_helix_up_large"}
  24. place_pieces
    {"pieces":["right_helix_up_small","right_helix_up_small","right_bank_to_flat","flat","flat"]}
    {"circuit_closed":false,"cursor":{"bank":4,"dir":3,"slope":0,"x":31,"y":74,"z":128},"placed_this_call":1,"rejection":{"error":"Twister Roller Coaster 1 in the way","index":1,"piece":"right_helix_up_small"},"total_placed":46}

  25. Full 360° helices won't fit this coaster's clearance. Switching lever: unbanked turns at high speed (identical geometry, big lateral-G spike).

  26. undo_piece
    {"cursor":{"bank":4,"dir":1,"slope":0,"x":28,"y":75,"z":112},"pieces_placed":45,"removed":"right_helix_up_small"}
  27. undo_piece
    {"cursor":{"bank":0,"dir":1,"slope":0,"x":28,"y":74,"z":112},"pieces_placed":44,"removed":"flat_to_right_bank"}
  28. place_pieces
    {"pieces":["flat_to_up_25","up_25_to_flat","flat_to_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","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25","down_25","down_25_to_flat","flat","right_turn_5","flat","flat_to_up_25","right_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","left_corkscrew_up","right_corkscrew_down","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","right_turn_5","flat","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_righ… (1314 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":70,"total_placed":114}
  29. finish_and_test
    {"bounds":{"max_tile_x":64,"max_tile_y":104,"max_z":344,"min_tile_x":25,"min_tile_y":59,"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":"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_to_down_25","down_25","down_25","down_25","down_25_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain… (2941 chars)

  30. Identical ratings — turn banking didn't move the needle. Bigger lever: **half-loop pair** (+2 inversions, and its net displacement equals 2 flats, so geometry stays closed).

  31. demolish
    {"demolished":0}
  32. 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}
  33. 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":"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_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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",{"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":tr… (1666 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":1,"slope":0,"x":28,"y":101,"z":112},"placed_this_call":71,"rejection":{"error":"piece enters at 25-up slope but the track here is flat; add a slope transition piece first","index":71,"piece":"half_loop_up"},"total_placed":71}

  34. Half-loop needs a 25° entry — adding transitions makes the block net exactly 4 flats. Recomputing the return leg.

  35. place_pieces
    {"pieces":["flat_to_up_25","half_loop_up","half_loop_down","down_25_to_flat","right_turn_5","flat","flat","flat_to_up_25","right_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","left_corkscrew_up","right_corkscrew_down","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","right_turn_5","flat","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","s_bend_right","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","flat","flat","flat","flat","brakes","brakes","brakes","right_turn_5"]}
    {"circuit_closed":false,"cursor":{"bank":15,"dir":3,"slope":0,"x":28,"y":102,"z":272},"placed_this_call":2,"rejection":{"error":"Twister Roller Coaster 1 in the way","index":2,"piece":"half_loop_down"},"total_placed":73}

  36. Half-loop folds back over the drop track. Out of time to re-plan around it — restoring the proven tail to leave a valid closed circuit.

  37. undo_piece
    {"cursor":{"bank":0,"dir":1,"slope":2,"x":28,"y":102,"z":120},"pieces_placed":72,"removed":"half_loop_up"}
  38. undo_piece
    {"cursor":{"bank":0,"dir":1,"slope":0,"x":28,"y":101,"z":112},"pieces_placed":71,"removed":"flat_to_up_25"}
  39. place_pieces
    {"pieces":["flat","right_turn_5","flat","flat_to_up_25","right_vertical_loop","down_25_to_flat","right_corkscrew_up","left_corkscrew_down","left_corkscrew_up","right_corkscrew_down","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","right_turn_5","flat","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","s_bend_left","s_bend_left","s_bend_left","s_bend_left","s_bend_right","flat_to_up_25","up_25_to_flat","flat_to_down_25","down_25_to_flat","brakes","brakes","brakes","right_turn_5"]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":0,"slope":0,"x":60,"y":60,"z":112},"placed_this_call":43,"total_placed":114}
  40. finish_and_test
    {"bounds":{"max_tile_x":64,"max_tile_y":104,"max_z":344,"min_tile_x":25,"min_tile_y":59,"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":"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_to_down_25","down_25","down_25","down_25","down_25_to_flat","flat","flat_to_up_25","left_vertical_loop","down_25_to_flat","flat_to_right_bank","banked_right_turn_5","right_bank_to_flat","right_corkscrew_up","left_corkscrew_down","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",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain… (2941 chars)

  41. Score confirmed and a valid closed circuit is standing. Let me record this round's findings.

  42. Edit
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-contest-tactics.md","new_string":"**Scoreboard: 7.13 @ intensity 10.17 (round 4) is still the all-time best. Round 6 = 7.07 @ 8.08. Round 5 = 6.94 @ 8.19.**\n\n**Round-6 findings — the \"raise intensity to ~10\" plan FAILED to find a working lever. Three dead ends, all confirmed by measurement:**\n- **A 360-degree helix is unbuildable on this coaster.** Both `*_helix_up_large` + `*_helix_down_large` AND two consecutive `*_helix_up_large` are rejected with \"Twister Roller Coaster 1 in the way\" — 16 units of climb per 180-degree half is not enough vertical clearance to stack. Small helices fail identically. Helix pieces are only usable as *single* 180-degree half-turns (i.e. just a banked turn that gains/loses 16), which is not an intensity lever. Do not spend time here again.\n- **Unbanked turns change NOTHING.** Swapping `flat_to_right_bank`/`banked_right_turn_5`/`right_bank_to_flat` for `flat`/`right_turn_5`/`flat` (identical geometry, drop-in substitution) at two high-speed turns produced a byte-identical eval report: same 7.07 / 8.08 / max_lateral_g 2.80. Lateral G was already saturated at 2.8 from the… (2747 chars)
    The file /home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-contest-tactics.md has been updated successfully.
  43. best_result
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  44. Round 6 is banked at **excitement 7.07**. **What happened:** I rebuilt the proven skeleton from memory and closed the circuit on the first try (114 pieces, similarity 0.32 — safely under the 0.5 penalty), banking 7.07 immediately. That already beat last round's 6.94. I then spent the rest of the budget hunting the "+2 intensity" the memory playbook predicted would be worth ~7.1+. All three levers failed, and I verified each rather than assuming: - **360° helices are unbuildable here** — up+down and up+up both rejected as "in the way"; 16 units of climb per half-turn isn't enough clearance to stack. Small helices fail the same way. - **Unbanked turns did literally nothing** — a geometry-identical swap at two high-speed turns returned a byte-identical eval report. Lateral G was already saturated at 2.80. - **The half-loop pair reverses direction**, so it always folds back onto the track it just arrived on. Geometrically it's a perfect drop-in (nets exactly 4 flats), but it collides everywhere there's enough speed to clear its 152-unit climb. I restored the working tail and re-tested to leave a valid closed circuit standing, confirming 7.07. Two things worth flagging honestly: I did **not** beat round 4's all-time 7.13, and the memory's central hypothesis — that intensity ~10.1 is the sweet spot to steer toward — turned out to have no reachable steering mechanism. I've rewritten that memory entry with the three dead ends and a new hypothesis: round 6 beat round 5 by *cutting* ~11 pieces of dead return-leg track, not by adding thrills, so shorter dead track may be the real lever. One caveat on the intensity theory itself: it rests on three data points across rounds where the layouts also differed, so the "9.8–10.2 sweet spot" may be reading causation into what was really round 4's layout being better. Next round I'd test drop depth (208→288) and dead-track removal directly. **Best coaster: a 114-piece dual-lift twister with two 208-unit drops, 2 vertical loops and 3 corkscrew inversions — excitement 7.07, intensity 8.08, no crash.**

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