BEHAVIOR Challenge 2026 — task 20 (sorting_vegetables), fine-tune ft1, step 9999
Selected checkpoint for the BEHAVIOR-1K 2026 submission.
Model
- Architecture: the 2025 BEHAVIOR Challenge winner's pi0.5-based policy
(IliaLarchenko/behavior-1k-solution, ~3B params, task-ID embeddings, no language prompt).
- Init: the winner's task-specific
checkpoint_2 (50 task slots).
- Training config:
pi_behavior_b1k_2026_task20 (in our pipeline repo's behavior-1k-solution/src/b1k/training/config.py).
- Data: 2026 challenge demos, task 20 episodes 4000-4179 (last 20 held out), RGB cameras only.
- Recipe: 10,000 steps (final step is 9999), batch 16, peak lr 5e-5, 1x A100 80GB. Final training loss 0.295. W&B run
599dnmgc.
- Checkpoint is params-only (no optimizer state): it can be served or used as an init, not
--resumed.
Layout
params/ — orbax/ocdbt parameters
assets/b1k_2026_task20/norm_stats.json — normalization stats
_CHECKPOINT_METADATA
Serve with scripts/serve_b1k.py --task-id 20 policy:checkpoint --policy.config pi_behavior_b1k_2026_task20 --policy.dir <this dir>.
Evaluation (local; q = fraction of goal predicates newly satisfied)
Scored the 2026 leaderboard way: public instances 0-9 (ids 301-310), one rollout each, default 1.5x
timeouts, task score = sum / 10.
Task 20 (13 goal predicates)
Leaderboard score: q = 0.1846 (sum 1.85 over 301-310; full completions: none)
| instance |
301 |
302 |
303 |
304 |
305 |
306 |
307 |
308 |
309 |
310 |
| q |
0.154 |
0.462 |
0.308 |
0 |
0.462 |
0 |
0 |
0.077 |
0.077 |
0.308 |
- Checkpoint choice, screened on held-out instances 311-315 (mean q): step 8000 = 0.092, step 9999 = 0.192.