[euanai]

Great questions!

Phase gates are hard — it's a PreToolUse hook (phase-gate-guard.js) that checks prerequisites before allowing state.json updates. If something's missing, the write gets denied. Like Phase 1→2 won't pass without literature-review.md (>2000 words), ≥10 papers in metadata, and a references.bib. Phase 6→7 needs a completed tournament with a champion. No exceptions — the agent just can't advance. There are some softer warnings too, but the main gates are hard blocks.

For champion selection — it's Successive Halving. All hypotheses compete in Round 1 (15% of GPU budget), top half survive to Round 2 (30%), champion gets Round 3 (55%). Each round eliminates the bottom half by score. The score is a weighted mix of metric improvement, mechanism signal quality, compute efficiency, and novelty — weights shift depending on venue target (oral cares more about novelty, poster cares more about raw metric gains).