CHECK gates for the one-entry leaf memo: bit identity, search parity, determinism, interleaved timing on real probe seeds
MemoSearch (fast-search.hpp with the leaf call replaced by fastFairLeafMemo below ++work_) passes: leaf bit identity in the search's feeding order on probe games at d4s5 and d4s7; parity with FastSearch on every move (column, work, nodes, cache hits, completed depth); identical results at 1 and 4 threads; interleaved timing ratio >= 1.5x on real roots.
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No explanation has been written for this record yet.
Technical recordThe registered protocol
- Hypothesis
- MemoSearch (fast-search.hpp with the leaf call replaced by fastFairLeafMemo below ++work_) passes: leaf bit identity in the search's feeding order on probe games at d4s5 and d4s7; parity with FastSearch on every move (column, work, nodes, cache hits, completed depth); identical results at 1 and 4 threads; interleaved timing ratio >= 1.5x on real roots.
- Arms
Arm Name Entry point Manifest Candidate fast-engine-memo MemoSearch approaches/lifetime-objective/fast-engine-memo/gate.cpp– Comparator fair-d4 approaches/fair-expectimax/reference/fair-only-depth4.cpp– - Classification
- engineering
- Information boundary
- seed-free
- Benchmark tier
- CHECK
- Lifecycle
- completed
- Theories tested
- Primary metric
- leaf bit mismatches and search parity mismatches (must be zero)
- Secondary metrics
- memo hit rate
- interleaved timing ratio plain/memo (indicative under load)
- determinism mismatches
- Statistical unit
- not-applicable
- Uncertainty method
- not-applicable
- Data role
- previously-evaluated-development
- Seed leases
- none recorded
- Whole-origin split
- yes
- Reuse disclosure
- Probe games on previously opened development seeds 0xa5278000-0xa52784ff only (CHECK probes); no strength data; no new seed.
- Pass criteria
- 0 leaf bit mismatches at d4s5 and d4s7
- 0 action/work/node/hit/depth mismatches vs FastSearch
- 0 determinism mismatches across thread counts
- timing ratio >= 1.5 at both strata settings (indicative)
- On pass
- Record pass (engineering, mechanics-only); the memo may be adopted by cohort runners after their own gates are re-run; an idle-host timing measurement is owed before any throughput claim.
- On fail
- Record fail; do not adopt the memo in any cohort runner.
- Gate fixed before controlled data
- yes
- Resources
Wall seconds 1800 CPU threads 4 Max host bytes 4294967296 Max GPU bytes – GPU devices – - Stop conditions
- Stop on any rules, information-boundary, legality, determinism, or parity failure.
- Expected artifacts
runs/RUN-20260822T073338Z-48e4df54/gates.log
- Amendments
- none recorded
Technical recordResults recorded against this protocol
One-entry leaf memo (fast-engine-memo/MemoSearch) on real probe seeds: leaf bits 0/4,260 (d4s5) and 0/2,500 (d4s7) mismatches in the search's feeding order; parity with FastSearch 0 action/work/node/cache-hit/completed-depth mismatches over 160 (d4s5, 117,732,775 leaf calls) and 50 (d4s7, 119,607,901 leaf calls) moves; determinism 0 mismatches at 1 vs 4 threads; memo hit rate 61.74% (d4s5) and 68.47% (d4s7); interleaved timing plain/memo 1.581x (d4s5, 12 real roots x 3 reps) and 1.634x (d4s7, 6 roots x 2 reps) under load ~31, indicative. Engineering result: semantics-preserving; no strength claim.
- ✓0 leaf bit mismatches at d4s5 and d4s7 — observed: 0/4,260 and 0/2,500
- ✓0 parity mismatches vs FastSearch — observed: 0 over 160 and 50 moves
- ✓0 determinism mismatches — observed: 0 over 4 games
- ✓timing ratio >= 1.5 at both strata (indicative) — observed: 1.581 and 1.634 under load
Technical recordRecorded metrics
- d4s5
- boards
- 4,260
- mismatches
- 0
- hitRateFeedOrder
- 0.5655
- d4s7
- boards
- 2,500
- mismatches
- 0
- hitRateFeedOrder
- 0.6392
- d4s5
- moves
- 160
- mismatches
- 0
- leafCalls
- 117,732,775
- hitRate
- 0.6174
- d4s7
- moves
- 50
- mismatches
- 0
- leafCalls
- 119,607,901
- hitRate
- 0.6847
- games
- 4
- threads
- 1
- 4
- mismatches
- 0
- d4s5
- roots
- 12
- reps
- 3
- plainSeconds
- 7.1319
- memoSeconds
- 4.5098
- ratio
- 1.5814
- d4s7
- roots
- 6
- reps
- 2
- plainSeconds
- 12.5726
- memoSeconds
- 7.6951
- ratio
- 1.6338
- Timing ratios were measured on a host at load ~31 and are indicative; an idle-host, three-repeat measurement is owed before any throughput claim.
- Probe cohorts are small (210 parity moves); the bit-identity argument is structural and the gates are confirmation, not the proof.
- Not adopted by any cohort runner yet.
Agent contextHow to extend this record
To add a reader-facing explanation, write web/content/research/EX-20260822-leaf-memo-gates-b31e4e7f.mdx; it renders above this record on the next request. The registered protocol itself is in the technical record above.
Record file: research/experiments/EX-20260822-leaf-memo-gates-b31e4e7f.json, validated against research/schemas/experiment-v1.schema.json. Protocol hash: 90b1bf1822f53069221b1eea42a51d95f7416dca6762a4f637873cb23ed6e42a.
Registered by Claude Code / claude-fable-5.