We ran a published result again and got a different number
Same checkpoint, 500 episodes, one fixed seed.
The same run reads 80.0% at 20 episodes and 62.0% at 500. Stopping early would have produced a different headline.
What we ran
- Checkpoint
- lerobot/diffusion_pusht
- Task
- PushT · gym-pusht
- Episodes
- 500
- Seed
- 1000
- Stack
- LeRobot 0.3.2
- Machines
- Xeon 8 vCPU · RTX 4090
Getting it to run was the first finding
The published checkpoint predates the processor pipeline introduced in 0.3.3, and the official migration script crashes. 0.3.2 is the last version that loads it.
What could explain the gap
- 1 Most likely
Sampling noise
The gap is 1.6 standard errors. A difference this size arises by chance about one run in eight.
- 2 Possible
A different draw of episodes
The model card states no seed. PushT randomises every reset, so another seed is another 500 tasks.
- 3 Least evidence
The software underneath
We ran on library versions that postdate the claim. The hypothesis we can say least about — so it is last.
- ✕ Ruled out
Hardware
Both machines shared the seed and agree to within one episode.
The experiment that separates them is the same evaluation across several seeds — left open so the next number comes from someone else’s machine.
The honest part
This is not a claim that the model card is wrong. 1.6 standard errors is neither a confirmation nor a refutation. Separating a real gap from noise would take roughly 1,500 episodes.
We made this study’s own mistake, on ourselves. An interim note called an early 80-episode reading “converging.” It was an optimistic window; the correction stayed in the repo.
PushT is not humanoid work, and we do not present it as any. It is the first step of a chain — reproduce → measure → benchmark → humanoid → real world.
Everything is in the open
All 500 per-episode records, the environment fingerprint and the version bisection — every number here can be recomputed from them.
Forenly-AI-Lab/reproduction-001The Skill Layer for humanoid robots
Forenly AI turns real scenes into simulation where humanoids learn their skills — then transfers them onto the machine.