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.