SirRoboGarage/docs/ram_floor_exhaustion_ab.md

j162 — the FIRING FLOOR: exhaustion measurement + a re-sized A/B proposal

No battle, server, GUI or A/B was started for this job. Both knobs remain default-0.0; out/ModularBot was not rebuilt. Everything below the divider is a proposal awaiting the owner's explicit permission.

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MEASURED (common_libs/tests/measure_ram_exhaustion, offline, state only)

Same corpus as j160: 8149 closed-loop recordings / 35163 rounds / 34.46M ticks. No counterfactual replay (the offline harness scored 0/6 on closed-loop questions, docs/offline_harness_trust.md).

1. We die BROKE, and it is a death event — not a state we sit disabled in

• 21865 rounds (61.2%) end with self energy crossing 0; 99.0% of rounds end in some death. Energy on the last tick we were alive: median 0.83, mean 2.50, p90 8.90, max 24.83. 55.9% of self-deaths at <=1, 84.2% at <=5, 92.8% at <=10, 100% at <=20.
• Time at energy <= 0 before the round ends: median 1 tick (p90 18). The round ends on the crossing tick. The 1.72%-of-ticks figure is dominated by a handful of recordings that hold a dead bot for hundreds of ticks — a recorder artefact, not a lived state. There is no recoverable disabled window to defend.
• The reserve that would have absorbed the killing blow (the overshoot of the final hit): median 0.40, p75 2.00, p90 6.90, p99 15.0. A free 5-energy reserve would have saved 85.1% of self-deaths.

So the prompt's hypothesis ("it dies at 40 energy, so the floor protects against nothing") is false: the bot dies with nothing, every time. The floor's premise is real.

2. We cannot climb back out of a low-energy dip

Energy rises on 0.598% of tick-pairs (~5.87 landed hits/round; mean landed power 1.42, mode 1.0 — not 0.1). Per tick spent at a given level:

energy	climb next tick	killed this tick	ratio
<= 3	0.130%	0.830%	dying 6.4x more likely
<= 5	0.232%	0.663%	dying 2.9x more likely
<= 10	0.365%	0.437%	dying 1.2x more likely
<= 20	0.500%	0.256%	recovering 2x more likely

Below ~10 energy a landed hit is not coming; below 20 it usually is. A floor at 20 would therefore block the only zone where recovery is actually plausible.

3. What the floor costs

floor	% ticks blocked	rounds	med run	p90 run	mean run	% runs ending in death	bank @1.0p
3	7.64%	23086	34	299	98	80.8%	8.2
5	9.58%	23739	53	330	118	78.0%	9.9
10	14.52%	25211	89	433	162	70.3%	13.5
20	24.74%	27799	139	621	236	60.0%	19.6

"Bank" = mean suppressed run x p/(10+2p) energy/tick, the gun-heat ceiling (heat = 1 + p/5, cool 0.1/tick). At 0.1 power it is 0.52 energy for floor 5; at 2.0 power, 16.9.

Measured caveat, and it matters: the recorded energy ledger closes exactly — start + landed-gains - damage - end = -0.00 over 35065 rounds. These captures do not charge the firepower cost, so the cost column is derived from the game rules, not read off the data. The landed-hit power distribution is read off the data (mode 1.0, mean 1.42) and is what sets the bracket.

4. Honest read — materially DIFFERENT from the geometry arm

Firing is net energy-negative for this bot on this panel: a landed hit returns 3p for p spent (break-even hit rate 1/3), and the hit rate cannot exceed 5.87 hits / 76 shots-per-round heat ceiling = 7.7%. So not firing really does bank energy — about 9.9 at floor 5.

That is the same kind of trade the geometry arm made — spend offence, buy protection — but a different magnitude:

• Safety claim is stronger. The geometry arm's safety gain did not convert into wins. Here the hazard is measured directly: 0.66%/tick death at energy <= 5, against a p75 overshoot of 2.0 and a bank of 9.9. The bank is above p75 and near p90 — a genuinely material reserve, not a rounding error.
• Damage cost is ~an order of magnitude smaller. Floor 5 suppresses ~4.4 shots per median run; at 4 damage/hit and a 7.7% hit rate that is ~1.4 damage per suppressed run, ~2 damage/run. The geometry arm lost 8.83 damage/run for its unconverted gain.
• It is a light touch in time, not in behaviour: 9.6% of ticks, median run 53 ticks. Not a blackout.

Verdict: the floor is worth an A/B. It is not the clean negative. But the honest counterweight is on the record: 78% of suppressed runs still end in death, and the bank is only reached because we stopped shooting.

Chosen value: TR_RAM_FLOOR_ENERGY=5 — bank 9.9 (above p75 overshoot 2.0, near p90 6.9) at 7.6%-vs-9.6% less tick cost than 10. Floor 20 is dropped on the measurement: it costs 24.7% of ticks and sits on top of the <= 20 recovery window.

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PROPOSAL — PRE-REGISTERED, NOT RUN

• Harness: tools/ab/tournament_run.sh + tools/ab/tournament_analyze.py, unmodified. Panel: tools/ab/panel_movement.txt (frozen 15-opponent movement panel). Unit of evidence is the opponent, not the battle. One frozen binary from git archive of j160-ramfloor.
• Contamination control — j159's three guarantees, unchanged: (1) per-arm TR_ENV_FILE in this job's own outdir (/tmp/j162_floor/env/<arm>.env); (2) the per-run botdir holds only .json, .sh and a symlink to the frozen binary — no .env, and the loader does not walk up; (3) every run's [env] boot report is checked against its arm, and any disagreement voids the session. A session-record check runs BEFORE analysis, not as a rewrite afterwards (j159 had a mid-analysis session.json rewrite; not repeated here).

arm	env	role
A_off	both unset	REFERENCE
B_floor	TR_RAM_FLOOR_ENERGY=5	the floor alone (value from the measurement)
C_exhaust	TR_RAM_ENEMY_ENERGY=20	the exhaustion trigger alone
D_both	TR_RAM_FLOOR_ENERGY=5 TR_RAM_ENEMY_ENERGY=20	the combined policy

No arm is inert, so none is dropped: C_exhaust=20 acts on 7.1% of ticks (enemy <= 20 while we are > 20) and D_both is the only arm that answers the composition rule. A floor sweep arm is deliberately omitted — the measurement chose the value, and the budget is better spent on n.

Size — corrected for the real throughput

j159 measured 420 battles in 1110 s = 23 battles/min (not the ~7/min the previous estimate assumed). MDE scales as 1/sqrt(n); the shipped default movement gate resolved 0.17 wins/run at 210 runs/arm. For a target MDE of 0.10 wins/run: n = 210 * (0.17/0.10)^2 = 607 runs/arm, rounded up to 42 runs/opponent = 630 runs/arm.

• 15 opponents x 4 arms x 42 runs x 3 rounds = 3780 battles ≈ 2.7 h.
• Decision-only 2-arm version (A_off vs B_floor): 15 x 2 x 42 x 3 = 1890 battles ≈ 1.4 h, still at MDE 0.10.

Metrics (fixed now)

Primaries: damage/run, round-win rate. Mechanism, never a verdict: self energy at death, ticks spent disabled, shots fired/run, ram-kill count. Paired per-opponent deltas, mean/SD/SE/95% CI, sign test, sign-flip permutation, Wilcoxon cross-check, reported MDE. Two-sided.

Verdict rule (fixed now)

Adopt only if BOTH primaries favour the arm with p(sign-flip) < 0.05 and the effect is at or above the reported MDE. Otherwise do not ship; both knobs stay 0.0. A clean null is a fully acceptable result. No subsetting, no dropping opponents, no re-running to chase a p-value.

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j163 — PRE-REGISTRATION: the FIRING FLOOR A/B (2 arms), BEFORE ANY BATTLE

Written and committed before a single battle of this design was run. Nothing below was chosen after seeing data. Worktree j160-ramfloor @ 64e23e2, one frozen binary built by tournament_run.sh from git archive HEAD, both knobs default-0.0, no code changed by this job.

Hypothesis

The bot dies broke: 61.2% of rounds (21865/35753) end with self energy crossing 0, and energy on the last alive tick is median 0.83. Below 5 energy the next tick brings death 2.9x more often than a landed hit (0.663%/tick vs 0.232%/tick); the bank of a suppressed run at floor 5 is ~9.9 energy against a p75 overshoot of 2.0 / p90 6.9 — a free 5-energy reserve would have saved 85.1% of self-deaths. Firing is net energy-negative here (a landed hit returns 3p for p spent; the hit rate is capped at 5.87/76 = 7.7%), so holding a reserve in the sub-5 zone should convert safety into round wins.

Arms — two, differing in exactly one variable (TR_MOVEMENT=tfil pinned)

arm	per-arm env file	role
A_baseline	TR_RAM_FLOOR_ENERGY=0	REFERENCE (today's shipped behaviour)
B_floor5	TR_RAM_FLOOR_ENERGY=5	treatment, the value chosen by the j162 measurement

The TR_RAM_ENEMY_ENERGY (ram-exhaustion) arm is DELIBERATELY EXCLUDED. Its own measurement found the trigger is rare at its literal threshold and that whether it fires is close to a coin flip in direction — it is not a well-founded mechanism. Excluding it here is a decision, not an oversight; this job tests only the one well-founded mechanism. If the floor is adopted, the exhaustion trigger needs its own design and its own A/B.

Primaries (fixed now)

1. round-win rate (rounds won / rounds fought) — the deciding primary
2. damage/run

THE DAMAGE MDE IS STATED UP FRONT, BECAUSE IT IS BIGGER THAN THE EFFECT

Expected damage cost of floor 5: ~2 damage/run (4.4 suppressed shots per median run x 4 damage/hit x 7.7% hit rate) — versus 8.83 damage/run for the already-rejected geometry arm. The design's damage MDE is 7.65. The damage effect is therefore ~3.8x below what this design can resolve.

Recorded before any data: we EXPECT TO BE UNABLE TO MEASURE THE DAMAGE COST DIRECTLY. A null on damage/run is the predicted outcome, not a surprise, and must NOT be re-read after the fact as evidence either for or against the floor. The verdict is judged on ROUND WINS. The damage MDE is a one-sided blind spot of this design, fixed in advance.

Counterweight (also on the record before any data)

78.0% of suppressed runs still end in death. The floor protects the tail of the energy ledger; it is not a shield. A mechanism-positive / outcome-null result is the fifth such in this campaign (j144, j145, j146, j147, j159).

Mechanism metrics (reported, never a verdict)

• self energy at death (per round);
• share of rounds ending at self energy <= 0 (baseline 61.2%);
• shots/run;
• share of ticks with firing suppressed (floor 5 predicts ~9.6% of ticks, median suppressed run ~53 ticks).
• Reported per opponent as well as pooled: j159's re-analysis showed a pooled test hid a real per-opponent effect (safety signal p=0.0008 per-opponent, null pooled). The unit of evidence is the opponent.

Size, MDE and the time floor

15 frozen opponents x 2 arms x 42 runs x 3 rounds = 1890 battles. MDE ~0.10 wins/run (210 x (0.17/0.10)^2; 210 was the design that resolved 0.17 wins/run). At the measured 22.7-23.2 runs/min that is ~1.4 h — a floor on elapsed time, not an estimate: opponent heterogeneity does not average down with added runs. If time runs short, the achieved n and the MDE actually reached are reported exactly; the panel and the arms are not silently shrunk.

Contamination controls (all three, in order)

1. Each arm is launched with TR_ENV_FILE pointing at a per-arm file this job generated in its own directory (/tmp/j163_env/<arm>.env) — never a shell export, because the dotenv loader gives the FILE priority. The file dir is deliberately outside --outdir (tournament_run.sh rm -rfs the outdir). This matters: the owner has an 18 KB .env at ModularBot_garage/out/.env in the main tree. The per-run botdir holds only .json, .sh and a symlink to the frozen binary; the frozen binary's own directory holds no .env; the loader's fallbacks are ./.env then exe-adjacent with no parent walk, so the owner's file is unreachable.
2. Every run's [env] boot block is verified against its arm as runs complete — TR_RAM_FLOOR_ENERGY and TR_MOVEMENT=tfil — and mis-set is counted and reported. A previous session was invalidated-risk because this was checked too late.
3. The session record is read before analysis, never rewritten. j159 had a mid-analysis session.json rewrite; declaring TR_MOVEMENT explicitly disables the analyzer's leaked-TR_MOVEMENT fatal check, so the built-in leak guard is not trustworthy here — the explicit per-run [env] verification above is the primary control. If the guard misbehaves it is reported as a finding, not worked around.

Verdict rule (fixed now, two-sided)

Adopt only if round-win rate favours B_floor5 with a per-opponent sign-flip permutation p < 0.05 AND the effect is at or above the reported MDE. Otherwise do not ship; TR_RAM_FLOOR_ENERGY stays 0.0. No subsetting, no dropping opponents, no re-running to chase a p-value, no reinterpreting the bar after seeing the data. A clean null is a fully acceptable result — and a null here licenses only "no effect >= MDE is detectable at this design", never "the knob is harmless".

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MEASURED

(appended after the battles — everything above was committed first, at 6cfb169)

MEASURED — the live A/B, 450 runs/arm, 2700 rounds (j163)

• Provenance. Frozen 15-opponent movement panel (tools/ab/panel_movement.txt), 15 x 2 x 30 runs x 3 rounds = 450 runs/arm, 2700 rounds, conc=6, 0 failed, 0 never started. Frozen binary d9a39c3b8472…, TR_MOVEMENT=tfil in both arms; the only difference is TR_RAM_FLOOR_ENERGY 0 (A_floor0, reference) vs 5 (B_floor5).
• Env verification — 0 mis-set. Every run's [env] boot block was checked against its arm as the session progressed, live at 24 / 193 / 410 / 826 / 900 runs completed: no disagreement at any checkpoint. Per-arm TR_ENV_FILE in the session's own directory, botdir without a .env, loader does not walk up parents. This is contamination control #2 from the pre-registration, satisfied.
• DEVIATION FROM THE PRE-REGISTRATION, DISCLOSED. The design asked for 42 runs/opponent (1890 battles, MDE ~0.10 wins/run). Measured throughput was 14-22 runs/min, not the assumed 22.7-23.2, so the wall-clock cost of the pre-registered n was not affordable. As the pre-registration required, the panel and the arms were NOT shrunk: the full 15 opponents and both arms were kept and the runs per opponent were reduced to 30. The MDE actually reached is reported below and is the honest resolution limit of this run. No opponent was dropped, no arm was re-run to chase a p-value.

Pooled dashboard (descriptive, NOT the verdict):

arm	runs	dmg/run	wins/run	round wins	round win rate
A_floor0	450	113.65	0.200	—	40.30%
B_floor5	450	112.70	0.182	—	39.70%

Verdict layer (per-opponent paired deltas, arm − reference; the sign-flip is the exact 2^15 permutation the pre-registration names as the decision test):

metric	mean Δ	95% CI	p(sign-flip)	sign test	Wilcoxon p	MDE reached
round-win rate	-0.59 pp	[-3.90, +2.72]	0.7676	1.00	0.84	4.73 pp
wins/run	-0.0178	[-0.117, +0.082]	0.7676	1.00	0.84	0.1420
damage/run	-0.95	[-3.88, +1.98]	0.5298	1.00	0.84	4.19

HEADLINE FINDING — the mechanism barely fired; the offline energy corpus did not survive contact with the live game

1. Suppression was 0.04% of ticks, not the 9.6% the offline ruler predicted — a ~200x smaller effect. The pre-registration's own mechanism metric (share of ticks with firing suppressed, predicted ~9.6%, median suppressed run ~53 ticks) is the number that failed, and it failed by two orders of magnitude.
2. Only 4.8% of shots are ever taken in the low-energy zone, and the floor removed 14% of those. The gate therefore touches a small slice of a small slice: a bot that almost never wants to fire at low energy. The pre- registration's expected damage cost (~2 damage/run) was the arithmetic consequence of the 9.6% figure; with 0.04% it is ~200x smaller still, which is why the damage MDE (4.19) is unreachable by construction and not by bad luck.
3. Rounds ending at self energy <= 0: 40.6% live vs 61.2% implied by the offline corpus (the j162 baseline the pre-registration quoted). The recorded-fixture corpus over-states how often we die broke by ~1.5x. This is the second, independent way the same corpus mis-called the live game.
4. Median self energy at death 14.1 -> 15.5 — the floor moved the death energy by +1.4, real but tiny, and nowhere near the "we sit disabled" state the floor was built for.
5. The pre-registered blind spot was called correctly. The pre-registration states, in advance, that we expect to be unable to measure the damage cost directly and that a damage null must not be re-read afterwards as evidence. That call was right, and it is the reason this run cannot be misread.

VERDICT — DO NOT ADOPT

1. The pre-registered verdict rule is not met. Adopt required round-win rate favouring B_floor5 with per-opponent sign-flip p < 0.05 AND the effect at or above the reported MDE. Observed: -0.59 pp against, p = 0.7676, under the 4.73 pp MDE. Round wins and wins/run are the same null (p = 0.7676, MDE 0.1420 wins/run).
2. TR_RAM_FLOOR_ENERGY stays 0.0. Do not adopt, do not ship, and do not re-test this knob. The design that could resolve a real effect does not exist at an affordable run count, and the mechanism it was built to suppress is nearly absent in the live game. Re-running buys resolution on an effect that is not there.
3. A null here does NOT prove the knob inert — the opposite. The mechanism fired on 0.04% of ticks. This run licenses only: "no effect >= 4.73 pp of round-win rate at 450 runs/arm". It says nothing about the ~0.04% of ticks it did suppress, because too few of them existed to measure.
4. The generalisable finding is the corpus, not the knob. The offline energy corpus over-predicted both the size of the low-energy firing window (9.6% -> 0.04%) and the rate of dying broke (61.2% -> 40.6%). An offline ruler built on recorded fixtures is only as representative as the fixtures; the death-energy corpus does not represent the live energy ledger. Future offline rulers for exhaustion must be calibrated against a live death-energy distribution before their predictions are pre-registered as expectations, not just as a rationale.

Ship state: unchanged. TR_RAM_FLOOR_ENERGY=0.0 and TR_RAM_ENEMY_ENERGY=0.0 remain the shipped defaults, and the ram path keeps its pre-j160 behaviour. This is the sixth mechanism-positive-or-presumed / outcome-not-positive result in the campaign (j144, j145, j146, j147, j159, j163) — and the first where the mechanism was not merely ineffective but ~200x smaller than the offline ruler said it would be.