Code Autopilot
Rules written by an AI coding agent (Claude) with the operator: six versions, tens of thousands of practice games.
< 0.1 ms$0
UFA JEV Bake-Off · Atari Space Invaders · September 2026
Code and data on GitHubThe UFA JEV Bake-Off asked
builders to play Atari Space Invaders with JEV, TypeSafe's new decision
model, and compare it with an LLM. The premise: An LLM that takes two
seconds to think is already dead. A decision model answers in about the time one frame takes.
Prove it.
We tested it: the same game, the same seeds, every decision measured.
Just holding the FIRE button outscored two LLMs and matched JEV. The Code Autopilot, running no model while it plays, beat all three by more than 50 times.
JEV still beat both LLMs, 12x faster and 35x cheaper.
Bars: the average of the same five games. Dots: each game. The models got the game as numbers (Tier 1).
Holding FIRE scores 285 in every game: the game has no randomness of its own, and the seed only changes when a button press repeats, which cannot change a player that never changes buttons.
Rules written by an AI coding agent (Claude) with the operator: six versions, tens of thousands of practice games.
< 0.1 ms$0
TypeSafe's decision model. Built on a language model, but it reads the odds of each option instead of writing an answer.
≈ 93 ms≈ $0.00004
Claude Haiku 4.5 and Qwen3.8 27B. Same question; they write the answer word by word.
≈ 1–2.4 s≈ $0.0014
Hold FIRE, or press random buttons. Anyone should beat these.
< 0.1 ms$0
The short answer: the autopilot sees the same screen as the models, and no more (like any player, it remembers what it saw a moment ago). It calculates where an alien will be when a shot arrives. The models have to guess, and mostly can't.
Hand a model raw positions, or distances already worked out, or the autopilot's own verdicts. The score follows.
Ten real frames. Pick a move, then see what the autopilot did.
In realtime the game does not wait. Frames that pass while each one thinks:
The aliens land. Each wave starts lower; wave 5 starts at the line, and so does every wave after it. In 99 practice games the autopilot (v6) lost 32 to a landing in waves 1 and 2, but 62 cleared wave 5 and most kept going: the longest games reached wave 38.
We added the autopilot's strategy to the question in plain words (dodge, aim at the lowest alien of the nearer edge column, aim ahead of it, fire when lined up) and checked each model's move on 300 real frames against the autopilot's.
JEV's guide recommends narrow questions. On the same 300 frames we asked JEV four, with only the positions (Tier 1), and compared its answers with the autopilot's calculations. A useful answer beats always guessing the most common one.
python -m invaders verify replays every autopilot game to the exact score.python3 -m venv .venv && .venv/bin/pip install -r requirements.txt export TYPESAFE_API_KEY=... ANTHROPIC_API_KEY=... .venv/bin/python -m invaders bench --players code,jev-t1,jev-t2,llm-t1,llm-t2 --seeds 101-105 --modes turn .venv/bin/python -m invaders verify