Add littlerock-1M (OpenCerebral)
Adds opencerebral/littlerock-1M, a public 1,002,720-parameter Llama-architecture model pretrained from scratch on 5B tokens (40% FineWeb-Edu / 60% DCLM-baseline) and then finetuned on public train splits. It loads with plain transformers (no trust_remote_code).
Evaluation: lm-eval 0.4.12, zero-shot, acc_norm, float32, CUDA. ArithMark-3 via your own bencharithmark-3.py (float32, default acc_norm).
| Model | ARC-Easy | ARC-Challenge | HellaSwag | PIQA | ArithMark-3 | Int Index |
|---|---|---|---|---|---|---|
| littlerock-1M | 30.98 | 21.08 | 26.55 | 53.81 | 40.40 | 6.69 |
The ArithMark-3 number is high for this size, so the provenance is up front rather than buried in the card.
- ArithMark-3 contributed zero training data. It has no train split -- its 1,000 items are the benchmark. Numeracy comes from elementary word problems generated from templates written independently for this project; ArithMark's own templates were not consulted.
- No scoring split was trained on. Finetuning used the train splits of PIQA, ARC-Easy and ARC-Challenge (train+validation), HellaSwag, OpenBookQA and SciQ. Scoring is on test/validation, which those do not overlap.
- Contamination guard. Every training string was checked against an index of all 16,428 items across all five scoring splits -- exact context, exact context+ending for every choice, and 13-gram overlap. It is validated with controls: it catches 200/200 real ArithMark items, 200/200 HellaSwag, 200/200 PIQA and 100/100 case/punctuation-edited variants, while flagging 0/3000 of the synthetic arithmetic. On the real corpus it found and dropped 221 genuine collisions -- HellaSwag's train split overlaps its own validation split via shared wikiHow sources, and OpenBookQA overlaps ARC.
- No checkpoint was selected on a benchmark. Selection used a held-out dev set: slices of the train splits never touched by training, plus arithmetic drawn from template families withheld from training, so the dev signal measures cross-phrasing transfer rather than template recall. The real suite was run only after selection was finished.
The per-topic breakdown from your script is the check on all of that:
| Topic | Score | In training distribution? |
|---|---|---|
| division | 72.2 | yes |
| multiplication | 56.8 | yes |
| time | 54.5 | yes |
| subtraction | 48.7 | yes |
| addition | 39.8 | yes |
| patterns | 13.2 | no |
| fractions: counting | 24.0 | no |
| two-step add/subtract | 15.2 | partially, did not transfer |
Performance is high on single-operation topics the generator covers and at or below chance (25.0) on topics it does not. Contamination or memorisation would raise every topic uniformly. Two-step chaining fails, which is a real limit: this model does one arithmetic operation, not two.
For reference, the same model before the finetune scores HellaSwag 26.37 / ARC-E 30.64 / ARC-C 21.50 / PIQA 52.29 / ArithMark-3 25.90 (Int Index 2.36). Essentially all of the gain is arithmetic; the language benchmarks are near a capacity wall at 1M parameters. Happy to submit the base checkpoint instead, or in addition, if you would prefer that.
Full methodology is on the model card. We have tried to follow the leaderboard's rules as we understand them, and everything above is disclosed so you can judge for yourselves -- if you determine that any part of this falls outside what you intend for the leaderboard, that is your call to make and we will accept it; we are happy to withdraw the submission or replace it with the base model.
Hi Klondike!
Firstly, I'd just like to say that getting a model at 1m parameters to generalize at this level on language arithmetic is a genuinely impressive feat. As not only did it score very highly on our public arithmark-3 set but also our private held out one. I also truly appreciate your transparency and honestly on this model and thus will attempt to return the favor with how we evaluate a model's suitability for ranking.
In truth there are 3 arithmark 3 sets, the public one, the private held out set (to test for pure memorization), and the private variety set with some questions that are slightly different (to test for benchmark specialization)
| Model | Public Set | Private Set | Variety Set |
|---|---|---|---|
| SmolLM2-135M | 39.2% | 36.5% | 34.0% |
| MobileLLM-R1-140M-base | 65.1% | 73.0% | 58.5% |
| GPT-X2.5-135M | 38.4% | 34.5% | 36.0% |
| littlerock-1M | 40.4% | 35.5% | 21.5% |
Now as you can see, while all the models do very well on the public and private sets, LittleRock-1M falls off a cliff on the variety set while the others generalize.
Because of this the team and I have decided the model is not suitable for ranking, however we would love to have the base model on our leaderboard, and due to how impressed we were with the arithmark 3 score, if its ok with you we would like to feature this model on a notable releases card.
Many thanks,
Dan
Hi Dan!
Thank you very much, both for the decision and for your explanation. This was more transparency than you owed me, and I greatly appreciate it!
The decision is correct and I'd have made the same one. The variety-set being below chance proves it, and I really appreciate showing me.
Please do list the base model. Verified with lm-eval 0.4.12 (zero-shot, acc_norm, float32) and your bencharithmark-3.py:
| Model | ARC-Easy | ARC-Challenge | HellaSwag | PIQA | ArithMark-3 | Int Index |
|---|---|---|---|---|---|---|
| littlerock-1M (base) | 30.98 | 21.76 | 26.43 | 52.23 | 25.20 | 2.29 |
1,002,720 parameters, pretrained from scratch on 5B tokens (40% FineWeb-Edu / 60% DCLM), no finetuning, open weights. I'll update the PR to point at the base checkpoint.
Not exactly an overwhelming force, but truthful nonetheless.
On the notable-releases card, yes absolutely, and thank you very much!
Thanks again,
Klondike
Superseded by #74, which carries the base checkpoint's verified numbers. I could not push to this PR's branch (no write access to the Space), so a fresh one was cleaner than leaving a stale row here. Closing this to keep the queue tidy -- thanks again for the thorough review. Action automated by Claude Code.
https://huggingface.co/opencerebral/littlerock-1M-arithmax -- old model. Let me know if you would like any changes.