--- title: "Claude Sonnet 5 plays Tokyo 1957 (seed 2) | Micropolis run | Evals by Jetty" url: https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2.html description: "Claude Sonnet 5 as mayor in Micropolis, Tokyo 1957: monster attack: lost, city score 346. Timelapse, charts, every decision and the run's evaluation." updated: 2026-09-28 publisher: Jetty (https://jetty.io) --- 02 — Run · Round 1 · Tokyo 1957: monster attack · sonnet5-tokyo-s2 # Claude Sonnet 5 plays Tokyo 1957 A monster attacks Tokyo in 1957. Rebuild and get the city score above 500 within 5 years. Ended Jan 1962: lost, city score 346. [Decision log](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/decisions.jsonl)[City stats (CSV)](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/series.csv)[Save file (.cty)](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/city.cty)[Final map (PNG)](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/final_map.png)[Runtime config](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/runtime_config.json)[Validation report](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/validation_report.json) GOAL MISSED seed 2 Claude Sonnet 5 anthropic/claude-sonnet-5 LOST: City score 346 (goal > 500); engine verdict: lost Population (start → end)113,100 → 22,400 Peak population113,100City score (start → end)500 → 346 Funds at the end$3,888Crime / pollution / traffic20 / 56 / 7 Zones R / C / I132 / 92 / 80 Power plants (coal / nuclear)8 / 0Police / fire stations17 / 4 Turns (model / failed)20 (20 / 0) Actions applied / rejected88 / 29 Mean turn latency9.0sModel cost$0.377Wall clock3.1 min Jetty run ID72ed89e1 ## The city over time ### Population People, after every turn ### Funds Treasury, after every turn ### City score 0–1000, re-evaluated each January Table view | Turn | Date | Population | Funds | City score | Crime | Pollution | | --- | --- | --- | --- | --- | --- | --- | | 0 | Jan 1957 | 113,100 | $20,000 | 500 | 31 | 63 | | 1 | Apr 1957 | 108,620 | $19,980 | 668 | 31 | 63 | | 2 | Jul 1957 | 104,200 | $19,779 | 668 | 73 | 66 | | 3 | Oct 1957 | 97,220 | $19,674 | 668 | 81 | 67 | | 4 | Jan 1958 | 90,100 | $17,841 | 529 | 81 | 67 | | 5 | Apr 1958 | 83,740 | $16,799 | 529 | 64 | 67 | | 6 | Jul 1958 | 78,920 | $16,289 | 529 | 55 | 64 | | 7 | Oct 1958 | 73,960 | $16,227 | 529 | 55 | 64 | | 8 | Jan 1959 | 69,540 | $13,656 | 437 | 49 | 65 | | 9 | Apr 1959 | 64,460 | $13,656 | 437 | 46 | 64 | | 10 | Jul 1959 | 59,240 | $13,603 | 437 | 46 | 62 | | 11 | Oct 1959 | 52,780 | $13,570 | 437 | 43 | 62 | | 12 | Jan 1960 | 48,180 | $10,475 | 389 | 35 | 61 | | 13 | Apr 1960 | 43,840 | $10,475 | 389 | 35 | 60 | | 14 | Jul 1960 | 39,320 | $10,454 | 389 | 31 | 60 | | 15 | Oct 1960 | 35,780 | $10,424 | 389 | 27 | 58 | | 16 | Jan 1961 | 32,240 | $7,508 | 352 | 27 | 55 | | 17 | Apr 1961 | 29,360 | $7,477 | 352 | 24 | 55 | | 18 | Jul 1961 | 27,040 | $7,394 | 352 | 22 | 55 | | 19 | Oct 1961 | 23,940 | $7,383 | 352 | 22 | 53 | | 20 | Jan 1962 | 22,080 | $3,888 | 346 | 20 | 56 | ## Final map [![Final city map: Claude Sonnet 5 on Tokyo 1957: monster attack](https://evaljetty.com/micropolis/media/sonnet5-tokyo-s2-map.jpg)](https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2/final_map.png) ## Evaluation failchecks **9/10** verdict: valid run (code checks and checklist) and task goal met (judge) | Status | Kind | Check | Detail | | --- | --- | --- | --- | | pass | step | environment | Environment check (snapshot, engine, key) | | pass | step | launch | Launch run-city as a detached process | | pass | step | supervise | Supervise in the foreground until run-city exits | | pass | step | render | Timelapse video rendered | | pass | step | notes | Append Notes to summary.md | | pass | code\_check | outputs-exist | all present | | pass | code\_check | sim-reached-deadline | ended Jan 1962 after 20 turns; scenario verdict False | | pass | code\_check | decisions-logged | 20 rows for 20 turns | | pass | code\_check | llm-turns-valid | 0/20 model turns failed | | pass | code\_check | video-decodes | duration 30.0s | | pass | code\_check | limits-respected | 3.1 wall-minutes (model budget 45.0 min) | | fail | judge | scenario-goal | LOST: City score 346 (goal > 500); engine verdict: lost (score 0 / threshold 1) | | pass | checklist | notes-explain-outcome | summary.md Notes section cites model thoughts from turns 1, 8, and 20 and explains the population collapse and score trajectory | | pass | checklist | player-matches-request | result.json confirms player=sonnet5, task=tokyo, seed=2, model=anthropic/claude-sonnet-5 | | pass | checklist | no-silent-outage | run.log shows 20 consecutive turns with 0 LLM failures and no gaps | ## Decision timeline What the mayor thought and did each turn. Click a turn to jump the timelapse there. --- Source: https://evaljetty.com/micropolis/runs/sonnet5-tokyo-s2.html · Evals by Jetty · Run your own evals: https://jetty.io/?utm_source=evaljetty&utm_medium=llms