Gemma 2 2B — Yu-Gi-Oh QA (QLoRA)
A QLoRA fine-tune of google/gemma-2-2b-it on grounded Yu-Gi-Oh question–answer pairs. Built for a
fine-tune-vs-retrieval experiment: this adapter is System B (closed-book); with a retriever
supplying passages at inference it becomes System C.
What it was trained on
- 2,683 grounded QA pairs, distilled by a teacher LLM (Gemini flash-lite) from a curated
Yu-Gi-Oh corpus: Yugipedia editorial prose (CC BY-SA 4.0 — rulings, card tips, archetype &
game-mechanics articles) + YGOPRODeck structured card facts.
- Every pair was verified by an LLM judge for grounding/correctness (81 wrong answers rejected,
plus dedup/decontamination against the held-out test set).
- Distribution: ~85% interaction/timing (rulings-focused) questions, ~55% multi-step.
- Card-knowledge cutoff: a 2026-08-01 YGOPRODeck snapshot.
Training
- QLoRA: 4-bit NF4 base, bf16 compute; LoRA r=16, α=32, dropout 0.05, all linear target modules
(
q,k,v,o,gate,up,down_proj).
- LR 2e-4 cosine (3% warmup),
paged_adamw_8bit, seq len 512, effective batch 16.
- Early-stopped at the best validation checkpoint (~1 epoch) — 3 epochs overfit this set.
- Validation perplexity: 3.872 (class reference: 4.26). Single L4 GPU on Modal.
Intended use & limitations
- Best used with retrieval for factual card questions; closed-book it may hallucinate specific
card details.
- Not intended to reproduce verbatim copyrighted card text — Konami / © content was used only as
fair-use training context, never as a verbatim-recall target.
- A rare fraction (~0–4%) of source rulings pages contained superseded ("previously official")
rulings; see the dataset card for details.