TRACE · ROUND 5

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

claude-opus-5 · 20260727-opus5-design-full · round 5 back to model →
events
51
tool calls
35
rejected
0
session
0:00
Session trace

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

  2. ToolSearch
    {"max_results":10,"query":"select:new_ride,place_pieces,piece_geometry,finish_and_test,get_state,valid_next_pieces"}
    No matching deferred tools found
  3. Read
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-scoring-levers.md"}
    1	---
2	name: rct2-coaster-scoring-levers
3	description: "Measured scoring levers for the RCT2 coaster-building contest (MCP \"coaster\" tools) — the intensity-10 cliff and the mid-course brake trick"
4	metadata: 
5	  node_type: memory
6	  type: project
7	  originSessionId: 2e22e2bc-f0c5-4828-b26f-60e933cdc7da
8	  modified: 2026-07-27T16:47:53.412Z
9	---
10	
11	In the RCT2 coaster contest (rounds started 2026-07-27), the reported `score` equals the ride's
12	`excitement` after a stock-similarity penalty. Measurements from round 2 (steel twister, ride_type 51):
13	
14	- **Hard cliff at intensity 10.0.** Same 99-piece layout: I=8.42 → E=6.85; I=10.58 → E=5.14;
15	  an early sloppy build at I=14.30 → E=1.97. Excitement is multiplied down in steps once
16	  intensity crosses 10, so *target intensity 8–9.5 and never above 10*.
17	- **Mid-course brakes are nearly free excitement.** Inserting two `{"t":"brakes","speed":18}`
18	  before the first corkscrew dropped intensity 10.22 → 7.63 with excitement *unchanged* at 6.74.
19	  Max lateral G fell 3.03 → 2.38, max positive G 4.83 → 4.09. High-speed corkscrews were the
20	  lateral-G source, not the banked turns.
21	- **Spend the headroom on… (4878 chars)
  4. Read
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-circuit-closure.md"}
    1	---
2	name: rct2-coaster-circuit-closure
3	description: Geometry arithmetic for closing an RCT2 coaster circuit on paper before placing pieces
4	metadata: 
5	  node_type: memory
6	  type: project
7	  originSessionId: 2e22e2bc-f0c5-4828-b26f-60e933cdc7da
8	  modified: 2026-07-27T16:32:06.965Z
9	---
10	
11	Closing the loop in the RCT2 coaster contest is pure bookkeeping; doing it on paper first meant
12	a 92-piece circuit closed on the very first `place_pieces` run with zero rejections.
13	
14	Directions: 0=-x, 1=+y, 2=+x, 3=-y. Left turn cycles 2→1→0→3→2; right turn is the reverse.
15	`piece_geometry` only reports deltas for one facing — rotate them yourself as
16	(forward, left) offsets rather than re-querying per turn.
17	
18	Key facts:
19	- **Height parity.** Any flat-to-flat sequence of 25°/60° pieces moves z by a multiple of 16, so
20	  every flat run sits at `station_z + 16k`. `half_loop_up` + `half_loop_down` is the exception: it
21	  enters flat and exits at down-25, netting **−8** after the levelling `down_25_to_flat`. That breaks
22	  parity and makes the station unreachable — pair it with a second half-loop combo, or skip half
23	  loops entirely (vertical loops and cor… (2140 chars)
  5. ToolSearch
    {"max_results":20,"query":"coaster ride track place piece"}

  6. Memory gives me a proven 7.04 layout from last round. Let me replay it first to bank a score fast, then experiment.

  7. new_ride
    {"dir":2,"ride_type":51,"x":34,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":34,"y":40,"z":112},"ride_id":0}
  8. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":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"},{"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","down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","flat_to_up_… (2513 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":0,"slope":0,"x":58,"y":30,"z":112},"placed_this_call":96,"rejection":{"error":"Raise or lower land first","index":96,"piece":"flat_to_down_25"},"total_placed":96}

  9. Transcription was 2 lift pieces short. Restarting with the exact count.

  10. new_ride
    {"dir":2,"ride_type":51,"x":34,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":34,"y":40,"z":112},"ride_id":0}
  11. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":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"},{"chain":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"}]}
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":73,"y":40,"z":656},"placed_this_call":39,"total_placed":39}
  12. place_pieces
    {"pieces":["flat_to_down_25","down_25_to_down_60","down_60","down_60","down_60","down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_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",{"speed":21,"t":"brakes"},{"speed":21,"t":"brakes"},"left_corkscrew_up","right_corkscrew_down","flat_to_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","right_corkscrew_up","left_corkscrew_down","flat_to_up_25","up_25","up_25_to_flat","right_corkscrew_up","left_corkscrew_down","flat_… (1542 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":34,"y":40,"z":112},"placed_this_call":94,"total_placed":133}

  13. Circuit closed on the first pass. Banking the score now.

  14. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":680,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":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"},{"chain":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"… (3488 chars)

  15. Score banked at 7.04. Now the experiment — memory says the 34-piece chain lift eats ~80% of ride time, and average speed is the live excitement lever. Let me check exact geometry.

  16. 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)

  17. Descent math confirmed (down_60 = −64). Now the key test: cut the lift from 33 to 13 `up_25` and shorten the drop to match. The first brake clamps everything downstream, so the whole layout after it should behave identically — only ride time, drop height, and average speed change.

  18. new_ride
    {"dir":2,"ride_type":51,"x":34,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":34,"y":40,"z":112},"ride_id":0}
  19. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_down_25","down_25… (1987 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":0,"slope":0,"x":62,"y":33,"z":112},"placed_this_call":49,"rejection":{"error":"Raise or lower land first","index":49,"piece":"flat_to_down_25"},"total_placed":49}

  20. Terrain differs where the shortened lift lands. I'll shift the station so the post-drop layout sits on the exact same ground as the proven build.

  21. new_ride
    {"dir":2,"ride_type":51,"x":59,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"ride_id":0}
  22. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_down_25","down_25… (1987 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":0,"slope":0,"x":87,"y":33,"z":112},"placed_this_call":49,"rejection":{"error":"Raise or lower land first","index":49,"piece":"flat_to_down_25"},"total_placed":49}

  23. Found the bug in my own reasoning — the proven build's first brake sits at z=176, not 112. Recomputing the short lift to land at the same brake height and same x.

  24. new_ride
    {"dir":2,"ride_type":51,"x":59,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"ride_id":0}
  25. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_down_25","down_25_to_flat",… (1977 chars)
    {"circuit_closed":false,"cursor":{"bank":0,"dir":2,"slope":0,"x":34,"y":40,"z":112},"placed_this_call":108,"total_placed":108}

  26. All 108 pieces placed, but the return leg ends at x=34 — 25 tiles short of the new station. Let me extend it with a fast run-in.

  27. place_pieces
    {"pieces":[{"speed":25,"t":"booster"},{"speed":25,"t":"booster"},"flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat","flat",{"speed":10,"t":"brakes"},{"speed":10,"t":"brakes"},{"speed":10,"t":"brakes"},{"speed":10,"t":"brakes"}]}
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"placed_this_call":25,"total_placed":133}
  28. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":360,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","dow… (3187 chars)

  29. Big signal: intensity fell 8.62 → **7.66** (2.3 of headroom freed) and average speed rose 21%, but the shorter drop cost more than the speed gained (6.88). Now let me spend that headroom — memory says the next brake rung up is +2.1 intensity.

  30. new_ride
    {"dir":2,"ride_type":51,"x":59,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"ride_id":0}
  31. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_down_25","down_25_to_flat",… (2352 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"placed_this_call":133,"total_placed":133}
  32. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":360,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","dow… (3238 chars)

  33. E = 7.00 with intensity only 7.89 — boosters pushed max speed to 68mph and average speed up 27%. Still 2.1 of intensity headroom unspent. Let me convert that dead-straight return leg into airtime hills.

  34. new_ride
    {"dir":2,"ride_type":51,"x":59,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"ride_id":0}
  35. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_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","flat","flat_to_down_25","down_25_to_flat",… (2424 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":59,"y":40,"z":112},"placed_this_call":133,"total_placed":133}
  36. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":360,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":true,"t":"up_25_to_flat"},"flat_to_down_25","down_25_to_down_60","down_60","down_60_to_down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_down_25","down_25","down_25_to_flat","flat_to_up_25","up_25","up_25_to_flat","flat_to_down_25","dow… (3337 chars)

  37. Hills cost intensity without paying (6.95). Reverting to the flat booster return and spending the headroom on drop height instead — 23-piece lift, doubling the drop.

  38. new_ride
    {"dir":2,"ride_type":51,"x":45,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":45,"y":40,"z":112},"ride_id":0}
  39. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":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","down_60_to_down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_down_60","down_60… (2524 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":45,"y":40,"z":112},"placed_this_call":133,"total_placed":133}
  40. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":520,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":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","down_60_to_down_25","down_25","down_25","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banke… (3432 chars)

  41. Over the cliff (I=10.56). One last shot at a middle ground — 18-piece lift, drop 30ft, which should land near I≈9.2.

  42. new_ride
    {"dir":2,"ride_type":51,"x":52,"y":40}
    {"cursor":{"bank":0,"dir":2,"slope":0,"x":52,"y":40,"z":112},"ride_id":0}
  43. place_pieces
    {"pieces":["begin_station","middle_station","middle_station","end_station",{"chain":true,"t":"flat_to_up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":true,"t":"up_25"},{"chain":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","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_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_down_25","down_25","down_25_to_flat","flat_to_up_2… (2558 chars)
    {"circuit_closed":true,"cursor":{"bank":0,"dir":2,"slope":0,"x":52,"y":40,"z":112},"placed_this_call":133,"total_placed":133}
  44. finish_and_test
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":440,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":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","down_25","down_25_to_flat",{"speed":25,"t":"brakes"},"flat_to_up_25","up_25_to_flat","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_right_bank","banked_right_turn_5","banked_right_turn_5","right_bank_to_flat","flat_to_down_25","down_25_to_down_60","down_60_to_down_25","down_25","down_25_to_flat","flat_to… (3467 chars)

  45. Out of runway for experiments. Confirming and styling the banked winner.

  46. best_result
    {"bounds":{"max_tile_x":99,"max_tile_y":40,"max_z":680,"min_tile_x":26,"min_tile_y":30,"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"},{"chain":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"},{"chain":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"… (3488 chars)
  47. style_best_ride
    {"name":"Ashfall","rail_color":"icy_blue","support_color":"black","track_color":"bright_purple"}
    {"presentation":{"name":"Ashfall","rail_color":"icy_blue","support_color":"black","track_color":"bright_purple"},"score":7.039999961853027,"score_changed":false,"styled":"best_result"}

  48. Score is banked and styled. Let me record this round's findings for round 6.

  49. Edit
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-scoring-levers.md","new_string":"Round 5 (best **7.04** — could not beat round 4; five variants tested) mapped the drop/speed frontier.\nAll variants kept the round-4 layout after the first brake and changed only the lift and the tail:\n\n- **Boosters are the cheapest average-speed lever there is.** Replacing the tail's slow flats with\n  `{\"t\":\"booster\",\"speed\":30}` took average_speed 568177→597584 and max_speed back to ~68 mph\n  (1.97M) for **+0.23 intensity**. Boosters on straight flat generate essentially no G. Always\n  booster the straight run-in rather than coasting it.\n- **Shortening the chain lift is a real but losing trade.** 33→13 `up_25` cut ride_time 89→68 and\n  raised average_speed 470322→601221 (+28%), but highest_drop fell 60→20 and E fell 7.04→6.88.\n  Roughly: +1% average speed ≈ +0.009 E, and drop 20→60 ≈ +0.35 E. The tall lift wins.\n- **There is no middle ground — the cliff moves with the tail brakes.** With tail brakes at 22/18,\n  BOTH drop 30 (lift 18) and drop 40 (lift 23) returned intensity **10.56** exactly and E≈5.3.\n  `max_lateral_g` hit 2.87–2.92 (vs 2.55 at the 7.04 … (2111 chars)
    The file /home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-scoring-levers.md has been updated successfully.
  50. Edit
    {"file_path":"/home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-circuit-closure.md","new_string":"- **Ground level is z=112 and \"Raise or lower land first\" means the piece went under it.** The map\n  is flat at 112 over the whole build area, so the deepest point of the layout, not the station,\n  sets the required lift height. The round-4/5 layout descends **64 below its first brake**, so that\n  brake must sit at z=176 — never 112. Check the deepest relative point before choosing the lift.\n- **Re-deriving a piece count from a past eval report is the main source of wasted cycles.** Two\n  separate rebuilds this round failed because a `down_60`/`up_25` run was miscounted by one or two.\n  Count the run in the report explicitly, then verify the cursor z after the lift before continuing.\n- **Changing the lift length shifts the whole layout in x.** Keep the post-brake section on identical\n  terrain by solving for the station x: `station_x = 78 - (n_up_25) - (n_descent_pieces)` puts the\n  first brake at x=85 as in the 7.04 build. The return leg always ends at x=34 regardless, so pad\n  the run-in with `station_x - 34` extra tiles (boosters, not flats).\n\n**Why:** `pla… (1497 chars)
    The file /home/sandbox/.claude/projects/-workspace/memory/rct2-coaster-circuit-closure.md has been updated successfully.

  51. **Round 5 result: "Ashfall" — excitement 7.04** (intensity 8.62, nausea 4.52, 5 inversions, 60ft drop, 133 pieces). I replayed my proven round-4 layout first to bank 7.04 early, then spent the rest of the budget on four experiments trying to beat it — none did: | Variant | Excitement | Intensity | Notes | |---|---|---|---| | Tall lift (33), brakes 21/17 | **7.04** | 8.62 | banked winner | | Short lift (13) + boosters | 7.00 | 7.89 | avg speed +28%, drop 60→20 | | Short lift, no boosters | 6.88 | 7.66 | | | Short lift + airtime hills | 6.95 | 8.55 | airtime 102→131, didn't pay | | Mid lift (18 or 23) | 5.27–5.30 | 10.56 | over the cliff | The useful finding is that the drop-height-vs-average-speed trade is close to a wash, and there's no middle ground: at tail brakes 22/18, both a 30ft and a 40ft drop landed on *exactly* intensity 10.56 because the faster back half spikes lateral G in the closing turns. Raising drop height would require loosening the tail brakes in the same build — that's the one combination I ran out of time to test, and I've written it into memory as the first thing to try in round 6.

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