Decisive measurement for the j160 firing floor, on the recorded closed-loop
corpus (8149 recordings / 35163 rounds / 34.46M ticks, state only):
* 61.2% of rounds end with self energy crossing 0. Energy at death: median
0.83, p90 8.90, max 24.83 -- the bot dies BROKE, so the floor's premise is
real. Time at energy<=0 is a median of 1 tick: the round ends on the
crossing tick, there is no recoverable disabled window.
* Reserve that would have absorbed the killing blow: median 0.40, p75 2.00,
p90 6.90.
* Cannot climb back out: at energy<=5 the next tick brings a landed hit 0.232%
of the time and death 0.663% (2.9x). At <=20 recovery is 2x more likely,
which is why a floor at 20 is the wrong value.
* Cost: floor 5 blocks 9.58% of ticks, median run 53, mean run 118, banking
~9.9 energy against a p75 overshoot of 2.0.
* Measured caveat: the recorded ledger closes exactly (residual -0.00 over
35065 rounds), so these captures do NOT charge firepower cost; the cost
column is derived from the game rules, and the landed-hit power (mode 1.0,
mean 1.42) is what sets the bracket.
Honest read: worth an A/B, materially different in magnitude from the geometry
arm (smaller damage cost, stronger and directly measured safety claim), so NOT
the clean 'protects against nothing' negative.
docs/ram_floor_exhaustion_ab.md: replaces the draft with the measurement plus a
re-sized A/B proposal (4 arms, 42 runs/opponent/arm, 630 runs/arm for MDE 0.10
wins/run, ~2.7 h at the measured 23 battles/min). NOT RUN -- no battle, server
or GUI was started. Both knobs remain default 0.0.
TR_RAM_FLOOR_ENERGY (0.0 = off): at/below this self energy we start no NEW
shot, holding back the reserve for a final ram exchange. Justified by the only
energy gain in the game being +3*power per bullet hit LANDED, so not firing
denies the enemy its only refill. Blocks only NEW shots (gunHeat already gates
committed ones) and is bypassed while ramming.
TR_RAM_ENEMY_ENERGY (0.0 = off): last-scanned enemy energy <= this -> ram
mode. Enemy energy IS observable (ScannedBotEvent.energy, schemas.nim:306),
1-8 ticks stale. This is the shipped finisher with its energy tolerance
promoted to a knob, keeping the self>enemy surplus guard because RAM_DAMAGE
0.6 applies to BOTH bots on every contact tick.
Open-loop measurement (measure_ramfloor_energy, 8149 recordings / 29871
rounds / 33.8M ticks): 'both low' is COMMON (10.4% of ticks below 20, 15.1%
below 25) but neither side goes low first (enemy 52.7% / us 47.3%), and the
owner's literal trigger - enemy so low it cannot fire (energy <= 1.95) - is
only 2.5% of ticks, 1.1% while we are healthy.
Guards 136 -> 147 in test_tfil_commit_env.nim, all green. A/B PRE-REGISTERED
in docs/ram_floor_exhaustion_ab.md and NOT RUN.
SirStone