tasks/dota2/instruction.md

Task: Reconstruct a Dota 2 match from an abstract top-down minimap video

You are given ONE video: a full Dota 2 match replayed on a clean top-down minimap (the real terrain minimap art), played back at 1:1 speed — one video second is one real game second. The video starts 8 seconds before the game horn: the horn (game clock 0:00) is at video second 8, so the game clock at video second video_ts is video_ts − 8. Nothing on screen names the heroes, the teams, the players, the score, the clock, or the map — you must infer everything from what the icons on the map do. An event's video_ts is still simply its time in seconds within the video (not the game clock). Anything that happens before the horn — a first blood or an early fight during the pre-game, even one before the video's first frame — is stamped at the horn, video_ts = 8.0.

What the minimap shows

• Two sides, told apart by GEOGRAPHY and COLOR, never by name. Radiant = green, based bottom-left (its Ancient sits in the bottom-left corner). Dire = red, based top-right. There is no other label; "radiant"/"dire" always means the green/bottom-left vs red/top-right side.
• Heroes = 5 team-colored numbered dots per side (1–5), each with a white halo for contrast. A hero that has just died fades to a faded ring for a moment. Dots have no portraits or names.
• Buildings are drawn with real minimap icon sprites, already team-colored (green = radiant, red = dire): towers (small squares along the three lanes), barracks (notched squares just inside each base), and the Ancient (the crystal/throne in each base corner). A building that is destroyed turns grey and dim — that greying is the visible moment a tower / barracks / ancient event happens.
• Roshan shows as an amber ring at the Roshan pit (top-side river). Roshan being killed is not spelled out; infer it from heroes massing on the pit and the ring/refresh.
• Creeps = small team-colored squares moving down the lanes; neutral camps = fainter tan squares in the jungle; runes = violet dots. These are context only — they are not events.

What to produce: ONE unified event list (answer.json)

Reconstruct every key event of the match in chronological order into a single list events. Each event answers everything at once: its perception fields (what/where/who) plus two per-event economy fields (minute_gain, leader_after) that describe the gold state around that event.

{
  "events": [
    {"type": "firstblood", "video_ts": 17.0, "killer_side": "dire",
     "minute_gain": "even", "leader_after": "even"},
    {"type": "tower", "video_ts": 579.0, "side": "radiant", "tier": 1, "lane": "mid",
     "minute_gain": "dire", "leader_after": "dire"},
    {"type": "teamfight", "video_ts": 964.0, "winner_side": "radiant", "deaths": 4,
     "minute_gain": "even", "leader_after": "dire"},
    {"type": "roshan", "video_ts": 1764.0, "killer_side": "dire",
     "minute_gain": "even", "leader_after": "dire"},
    {"type": "barracks", "video_ts": 2549.0, "side": "radiant", "rax_type": "range", "lane": "bot",
     "minute_gain": "dire", "leader_after": "dire"},
    {"type": "ancient", "video_ts": 2712.0, "side": "radiant",
     "minute_gain": "even", "leader_after": "dire"}
  ]
}

(The values above are made-up format examples, not from this game.)

Fields on every event

• type — one of: tower / barracks / ancient / roshan / teamfight / firstblood.
• video_ts — the video second (float) at which the event happens. Required — an event without it can never match. For a building, this is the second its icon greys out.
• Perception attribute(s) — depend on type:
  • tower → side (the side whose building fell, "radiant"/"dire"), tier (1–4), and lane ("top"/"mid"/"bot"). The two tier-4 base towers have tier 4 and no lane; omit lane for them.
  • barracks → side, rax_type ("melee" / "range"), and lane ("top"/"mid"/"bot").
  • ancient → side (the side whose Ancient was destroyed; this ends the game).
  • roshan → killer_side ("radiant" / "dire" — which team killed Roshan).
  • firstblood → killer_side (which side got the first kill of the game).
  • teamfight → winner_side ("radiant" / "dire" / "even" — the side that inflicted more deaths) and deaths (the total number of heroes that died in the fight, both sides combined).

The two economy fields (on every event) — INFERRED, not shown on screen

No gold number is ever displayed. You must infer the gold state from the flow of the game (kills, tower/rax/roshan control, map presence). Both fields are one of "radiant" / "dire" / "even", with "even" meaning the gap is within ±1000 gold. Let m = the whole game-minute the event falls in, counted from the horn: m = floor(max(0, video_ts − 8) / 60) (pre-game events fall in minute 0).

• minute_gain (FLOW) — which side gained more gold during the event's own minute [m, m+1] (≥1000 net swing; else "even"). This is momentum in that single minute, independent of who is ahead overall.
• leader_after (STOCK) — which side is cumulatively ahead by ≥1000 gold at the end of that minute (m+1), i.e. after this event has landed. It therefore includes this event's own gold impact plus all preceding history. (The key is named leader_after because it is the leader as of the whole minute after the event — the same convention as the other games.)

minute_gain and leader_after are independent: a losing side can win a single minute (e.g. minute_gain="radiant" while leader_after="dire").

Write answer.json as you go (required)

./answer.json is already in the sandbox — the harness created it before your first turn, with the schema above and an empty list:

{"events": []}

Do not delete it, do not rename it, and do not change the root key. Overwrite it in place — in full, valid JSON every time — as soon as you have something to put in it.

Then rewrite the whole file every time you finish a stretch of the video, adding the events you just found — do not save it all for the end.

• The file must be valid JSON at every moment: rewrite it in full each time (read → add → write back), never leave it half-written.
• Whatever is in answer.json when the run stops is what gets scored. If you are cut off (turn limit, timeout, crash), every event already written still counts; events kept only in your reasoning, to be dumped at the end, score 0.
• Each rewrite should contain everything the previous one had, plus the new events. If you are deep into the video and the file is not getting longer, you are overwriting instead of appending.
• Keep the rows sorted by video_ts. Do not delete a row you already wrote just because you are unsure — revise it in place if a later pass changes your mind.
• The two economy fields need the whole minute around the event, so fill them with your best current reading when you first write the row and revise them later if the game's flow changes your mind. That is a revision of existing rows, not a reason to delay writing them.

How you are scored

A single 1:1 time-matched F1 over the full event tuple. One of your events can pair with a ground-truth event of the same type with video_ts within tolerance (a few seconds), AND ALL of: the perception attribute(s) for that type, minute_gain, and leader_after. Any one wrong field — including either economy field — voids that event. Each ground-truth event pairs with at most one of yours; the judge takes the largest possible set of such pairs (and, of those, the one with the least total time error), so the order of your rows does not change the score. reward = F1 over matched events.

Notes

• The match runs ~20–70 minutes with sparse events; scan the WHOLE video, using every tool available over many rounds of tool calls (50+ preferred). Do not stop early — the game ends when one Ancient greys out.
• Report a teamfight only for a real multi-hero clash (several deaths clustered in time/space), not for every single kill.
• Output only answer.json with the single events key.

Tools (agentic mode)

You have ffmpeg (frame extraction), the ability to write code, and multi-turn tool calls. That is all you may use: do not download or install anything, and do not call any external service, API or model. This is a real professional match, so a search could hand you the gold graph and the result. Do not look it up — not the heroes, the teams, nor the outcome. Any network use voids the run — it is scored zero whatever answer.json contains.

What you may use

You are given the frames above and nothing else — there is no analysis tool, no code you can run, no file to write and no second turn. The gold-advantage fields have to be inferred from the minimap by you. If you happen to recognise this match, do not answer from memory: an answer that does not follow from the frames is not what is being measured.