Hypothesis under test (from the gun audit, which named the tie-band as "the
lever that matters most"): `bmPath` is deliberately generous (2.3-3.6x
`bmPoint`), so a gun can sit in the tied band on a ray that sweeps the target's
path while its bullets ARRIVE badly. So: keep the `path`-ranked band (path beat
point on real hit rate 7.43% vs 4.70%, z=5.56), but narrow the random draw
inside it using a parallel `point` (arrival-accuracy) window.
RESULT: NO EFFECT. Real DrussGT, ONE frozen binary (/tmp/ModularBot_tieband,
md5 2c0c56e6...), env knobs only, 7 runs x 7 rounds per arm, server-side events
sidecar, exact two-sided permutation test on per-run rates.
arm runs shots real % dmg/run d p
tbbase (shipped) 7 4128 7.17 175 -- --
tbpt path-rank + point-narrow 7 3938 7.08 165 +0.14 0.88
tbpc =commit control 7 3759 4.44 98 +2.74 0.0012
tbpt25 point margin 0.25 7 3683 5.59 119 +1.65 0.20
tbtie05 / tbtie40 (band width) 7 3937/3917 5.84/6.28 133/144 1.49/1.00 0.11/0.25
tbwin50 (SelectorWindow=50) 7 3983 6.05 139 +1.20 0.11
tbfloor10 (FloorPeakFrac=0.10) 7 3829 5.33 118 +2.12 0.11
tbpt vs base: fully overlapping ranges, p=0.88. This is a REAL null, not a dead
arm - the mechanism was live, and it visibly changed the selected-gun mix
(Pattern 24%->16%, Accel 6%->16%, Tsetlin ~0%->13%).
CONTROL VALIDATED, AND THIS IS THE THIRD TIME: removing the random draw inside
the band is SIGNIFICANTLY WORSE (4.44%, p=0.0012). Combined with the earlier
hysteresis A/B (7.02% -> 5.10% for commitment) and the light-hysteresis result,
the selector's per-tick randomness is now load-bearing on three independent
measurements. Narrowing the band on ANY second virtual statistic has not helped.
Every knob swept (band width, floor, window) is nominally worse than shipped at
n=7; that is "no credible win" rather than "proven harm" (sd ~1.8pp, ~1pp
resolution, underpowered).
Shipped default stays `GUN_SELECTOR_TIEBREAK=off`; the feature is opt-in, fully
guarded, and costs zero extra work on the default path (point windows are scored
only when the mode is on).
Guards: test_selector_tiebreak 19 (new, pure), test_gun_harness 39,
test_vbullet_metric 11, test_adaptive_radar 41, test_tfil_ring_weights 24,
test_power_policy 26, test_ram_decision 28, test_rack_membership 38,
acceptance_offline_vs_online 12/12 PASS (offline path calls neither
chooseFromFit nor the tie-break).
STRATEGIC CONCLUSION: three selection-side attempts have now failed (hysteresis,
commitment, point tie-break). The selector is at a local optimum and the
remaining lever is the QUALITY OF THE GUNS, not the selection among them.
