# r4-fresh merge 02: nine blind overlays on N, holdout 430000..430499 (paired vs N)

| rank | key | best spread | mean_diff (se) there | overall mean_diff (se) | flag |
|---|---|---|---|---|---|
| 1 | f-cash-reserve-decay | 3 | +0.0588 (0.1636) | -0.0397 (0.0528) | no |
| 2 | f-side-exposure-cap | 1 | +0.1345 (0.4383) | -2.8697 (0.5936) | no |
| 3 | f-phat-band-size | 1 | +0.0126 (0.1205) | -0.3451 (0.1395) | no |
| 4 | f-rival-inward-join | n/a | 0.0 (0.0) all spreads | +0.0000 (0.0000) | no |
| 5 | f-order-count-cap | 1 | -0.7515 (0.9348) | -10.7182 (1.3604) | no |
| 6 | f-age-size-decay | 1 | -4.1547 (2.5271) | -5.5055 (1.1735) | yes |
| 7 | f-microprice-shift | 1 | -12.9620 (4.7531) | -30.8753 (3.0866) | no |
| 8 | f-fill-burst-pause | 1 | -15.2614 (4.7220) | -35.8078 (2.8124) | yes |
| 9 | f-paired-size | 1 | -30.8399 (6.7779) | -88.4860 (4.8581) | yes |

No promotion: every overall holdout difference is <= 0; top three are within 0.4 se of zero on one spread. Inputs: the 9 item result.json files under .imd/reads/artifacts/ (item-f-*), copied, not recomputed; N = sha256 bf0d179f…ffae. No simulations run.

```json
{
 "rows": [
  {
   "key": "f-microprice-shift",
   "mech": "microprice shift",
   "spreads_acted": [
    1,
    2,
    3,
    4
   ],
   "off_equals_n": {
    "seeds": "310000..310009",
    "equal_every_step": true,
    "steps_per_seed": 2000
   },
   "code_sha256": "032ddde692ad498208dda62a07a9a59819fe2fb6b8bfb6ca870bc108a82c6d39",
   "assembled_sha256": "81ca9d5bb8ff5eccaf768e19ac4281a6d2a8928f3050f05be5694493768987d6",
   "complete": true,
   "h_n": 500,
   "incumbent_mean": 95.542015,
   "mean_diff": -30.875339,
   "se": 3.086592,
   "retail_diff": -32.743386,
   "arb_diff": 1.868046,
   "tuning_mean": -30.350936,
   "tuning_se": 4.996139,
   "by_spread": {
    "1": {
     "n": 131,
     "mean_diff": -12.962031,
     "se": 4.753095,
     "sum_d": -1698.026052,
     "sum_d2": 406750.158341
    },
    "2": {
     "n": 120,
     "mean_diff": -28.76354,
     "se": 4.846332,
     "sum_d": -3451.62474,
     "sum_d2": 434674.41935
    },
    "3": {
     "n": 133,
     "mean_diff": -42.428074,
     "se": 7.149785,
     "sum_d": -5642.933895,
     "sum_d2": 1136871.486736
    },
    "4": {
     "n": 116,
     "mean_diff": -40.043836,
     "se": 7.188507,
     "sum_d": -4645.084989,
     "sum_d2": 875346.61534
    }
   },
   "failures": [],
   "check_values_ok": true,
   "python_version": "3.14.4",
   "flag": null
  },
  {
   "key": "f-cash-reserve-decay",
   "mech": "Decaying cash reserve r(step) = r0 * steps_remaining / 2000; trim lowest-priority new orders.",
   "spreads_acted": [
    1,
    2,
    3,
    4
   ],
   "off_equals_n": {
    "passed": true,
    "seeds": "310000..310009",
    "simulations": 10,
    "steps_per_simulation": 2000,
    "steps_compared": 20000,
    "method": "Independent N and reserve_initial=0 overlay instances receive each identical StepState; action sequences compared by equality every callback in one N-equivalent trajectory per seed."
   },
   "code_sha256": "caa2006c0fa32051c1a6df8462948b3540b3619933ab342c3f6e3eaf2fc07878",
   "assembled_sha256": "1ba3a32eef28174df81ed0e06bb5ba35dc55016baa486be669f079ad6484afa8",
   "complete": true,
   "h_n": 500,
   "incumbent_mean": 95.54201511346659,
   "mean_diff": -0.039720983182800124,
   "se": 0.05279879389497742,
   "retail_diff": 0.011772989251399999,
   "arb_diff": -0.051493972433000065,
   "tuning_mean": -0.020700813612000036,
   "tuning_se": 0.07388117173201324,
   "by_spread": {
    "1": {
     "n": 131,
     "mean_diff": -0.11583803411068717,
     "se": 0.07952815471899553,
     "sum_d": -15.17478246850002,
     "sum_d2": 109.467924472143
    },
    "2": {
     "n": 120,
     "mean_diff": -0.07274235086000023,
     "se": 0.07357470171844521,
     "sum_d": -8.729082103200028,
     "sum_d2": 77.9359944996796
    },
    "3": {
     "n": 133,
     "mean_diff": 0.05876285316992471,
     "se": 0.1636477007192303,
     "sum_d": 7.815459471599986,
     "sum_d2": 470.61894475171226
    },
    "4": {
     "n": 116,
     "mean_diff": -0.03251798699396553,
     "se": 0.053496666335487074,
     "sum_d": -3.7720864913000014,
     "sum_d2": 38.30031740166342
    }
   },
   "failures": [],
   "check_values_ok": true,
   "python_version": "3.12.3",
   "flag": null
  },
  {
   "key": "f-paired-size",
   "mech": "paired sizing from own historical fill fractions",
   "spreads_acted": [
    1,
    2,
    3,
    4
   ],
   "off_equals_n": {
    "equal": true,
    "seeds": "310000..310009",
    "steps": 20000
   },
   "code_sha256": "7620ca65f64f77e47c6119780072497c6dc3f11bf8446af2186ca8627cb0a2c1",
   "assembled_sha256": "a94fd8177d33d8cdf176e0fa036cb80284086f445339e5b6a499c46be2bdc410",
   "complete": true,
   "h_n": 500,
   "incumbent_mean": 95.54201511346659,
   "mean_diff": -88.48600520516061,
   "se": 4.858128085159907,
   "retail_diff": -39.402075841275206,
   "arb_diff": -49.0839293639194,
   "tuning_mean": -88.00685668156349,
   "tuning_se": 6.523310810685201,
   "by_spread": {
    "1": {
     "n": 131,
     "mean_diff": -30.83987956066183,
     "se": 6.777857307879428,
     "sum_d": -4040.0242224467,
     "sum_d2": 906940.9855945596
    },
    "2": {
     "n": 120,
     "mean_diff": -80.67558052506,
     "se": 6.54499629148749,
     "sum_d": -9681.0696630072,
     "sum_d2": 1392737.9389524066
    },
    "3": {
     "n": 133,
     "mean_diff": -116.98493293157443,
     "se": 11.561713262786139,
     "sum_d": -15558.9960798994,
     "sum_d2": 4166935.050340116
    },
    "4": {
     "n": 116,
     "mean_diff": -128.99062618299138,
     "se": 10.269051230714659,
     "sum_d": -14962.912637227,
     "sum_d2": 3336824.0024057296
    }
   },
   "failures": {
    "count": 134,
    "tuning": [
     {
      "seed": 320000,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320003,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320007,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320008,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320009,
      "strategy": "slow",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320011,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320011,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320018,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320024,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320024,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320024,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320025,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320030,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320030,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320030,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320031,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320032,
      "strategy": "medium",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320032,
      "strategy": "slow",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320035,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320039,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320039,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320039,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320042,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320043,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320043,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320043,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320047,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320047,
      "strategy": "medium",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320047,
      "strategy": "slow",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320050,
      "strategy": "medium",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320050,
      "strategy": "slow",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320059,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320059,
      "strategy": "medium",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320064,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320069,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320083,
      "strategy": "medium",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320084,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320084,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320084,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320086,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320097,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320099,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320099,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320101,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320101,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320101,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320112,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320116,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320116,
      "strategy": "slow",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320117,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320120,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320120,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320120,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320121,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320122,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320122,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320130,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320131,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320131,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320135,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320141,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320144,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320148,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320149,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320149,
      "strategy": "medium",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320152,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320152,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320152,
      "strategy": "slow",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320155,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320155,
      "strategy": "medium",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320155,
      "strategy": "slow",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320158,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320161,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320161,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320166,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320169,
      "strategy": "medium",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320177,
      "strategy": "medium",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 320183,
      "strategy": "slow",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     }
    ],
    "holdout": [
     {
      "seed": 430015,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430016,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430024,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430027,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430050,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430051,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430052,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430065,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430089,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430096,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430104,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430114,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430122,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430124,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430134,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430140,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430144,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430161,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430172,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430175,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430193,
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      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430195,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430204,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430207,
      "strategy": "fast",
      "spread": 1,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430209,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430212,
      "strategy": "fast",
      "spread": 3,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430213,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430214,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430217,
      "strategy": "fast",
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      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430223,
      "strategy": "fast",
      "spread": 2,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430251,
      "strategy": "fast",
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      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430265,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430270,
      "strategy": "fast",
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      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430275,
      "strategy": "fast",
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     },
     {
      "seed": 430277,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430281,
      "strategy": "fast",
      "spread": 4,
      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430298,
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      "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral"
     },
     {
      "seed": 430302,
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     {
      "seed": 430322,
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     {
      "seed": 430326,
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     {
      "seed": 430331,
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     {
      "seed": 430341,
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     {
      "seed": 430345,
      "strategy": "fast",
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     {
      "seed": 430350,
      "strategy": "fast",
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     {
      "seed": 430372,
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     {
      "seed": 430386,
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     {
      "seed": 430388,
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     {
      "seed": 430394,
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     {
      "seed": 430417,
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     },
     {
      "seed": 430430,
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     {
      "seed": 430434,
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     {
      "seed": 430435,
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     {
      "seed": 430461,
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     {
      "seed": 430470,
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     {
      "seed": 430474,
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     {
      "seed": 430475,
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   "key": "f-rival-inward-join",
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   "key": "f-fill-burst-pause",
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    "passed": true,
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   "key": "f-phat-band-size",
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   "key": "f-side-exposure-cap",
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   "off_equals_n": {
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  {
   "key": "f-age-size-decay",
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    4
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   "off_equals_n": {
    "passed": true,
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    "method": "One unmodified engine trajectory per seed; a wrapper independently calls N and disabled overlay on the identical StepState and asserts action sequence equality each step."
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   "by_spread": {
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    "3": {
     "n": 132,
     "mean_diff": -3.001719498636363,
     "se": 1.4577366861813705,
     "sum_d": -396.2269738199999,
     "sum_d2": 37934.79732316672
    },
    "4": {
     "n": 115,
     "mean_diff": -9.283837329205218,
     "se": 3.0938365296655554,
     "sum_d": -1067.6412928586,
     "sum_d2": 135398.4269206029
    }
   },
   "failures": [
    {
     "stage": "discarded_initial_implementation",
     "seed": 320032,
     "variant_age": 20,
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "code_sha256": "e9e515d088c564de6ebd7b6a24157b6b20201a7e6aef1c41d1c5f84ef3106615",
     "resolution": "Attempted resizing surviving old orders before N actions. This did not eliminate later collateral failures. Discarded initial candidate scores; revised implementation evaluated at the same three A settings."
    },
    {
     "stage": "repaired_tuning",
     "seed": 320032,
     "strategy": "20",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320043,
     "strategy": "50",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320057,
     "strategy": "20",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320069,
     "strategy": "50",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320120,
     "strategy": "100",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320155,
     "strategy": "20",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320160,
     "strategy": "50",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320161,
     "strategy": "20",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "repaired_tuning",
     "seed": 320196,
     "strategy": "20",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "holdout",
     "seed": 430108,
     "strategy": "100",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "holdout",
     "seed": 430185,
     "strategy": "100",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "holdout",
     "seed": 430370,
     "strategy": "100",
     "error": "orderbook_pm_challenge.market.OrderBookError: Insufficient free cash for order collateral",
     "scored": false
    },
    {
     "stage": "protocol_deviation",
     "error": "Baseline inadvertently re-executed during repair restart, contrary to exactly-once requirement. Identical outputs were not counted twice. No holdout reruns.",
     "seeds": [
      320000
     ]
    },
    {
     "stage": "repair_disclosure",
     "error": "Tuning candidate executions for the discarded buggy source precede repaired-source executions on overlapping tuning seeds. Thus the strict at-most-three-source-variants interpretation and no-repeat protocol were not fully met, although only three age settings were tuned and final paired statistics use one repaired execution per seed/age.",
     "initial_completed_rows": 130,
     "initial_candidate_simulations": 97
    }
   ],
   "check_values_ok": true,
   "python_version": "3.12.3",
   "flag": "h_n=497 (<500); holdout incomplete, seeds 430108/430185/430370 failed (Insufficient free cash for order collateral); 14 failure records incl. 3 holdout, 9 tuning, 1 discarded build, 1 protocol deviation; incumbent_mean 94.5336 differs from the other rows' 95.5420 because the 3 failed seeds are excluded."
  }
 ],
 "top": [
  {
   "key": "f-cash-reserve-decay",
   "code_sha256": "caa2006c0fa32051c1a6df8462948b3540b3619933ab342c3f6e3eaf2fc07878",
   "assembled_sha256": "1ba3a32eef28174df81ed0e06bb5ba35dc55016baa486be669f079ad6484afa8",
   "code": "from orderbook_pm_challenge.types import PlaceOrder, CancelOrder, CancelAll, Side\nfrom orderbook_pm_challenge.utils import quantize_down\n\nclass Strategy(_N):\n    # Earlier new orders in N's action sequence have higher priority.\n    reserve_initial = 100.0\n    spreads_acted = (1, 2, 3, 4)\n\n    def on_step(self, state):\n        actions = super().on_step(state)\n        if self.reserve_initial <= 0 or self.s not in self.spreads_acted:\n            return actions\n        reserve = self.reserve_initial * state.steps_remaining / 2000.0\n        free = state.free_cash\n        # Existing SELL collateral allocations are not exposed. Treat all their\n        # quantity as covered when bounding free YES, and release no cash for\n        # individual existing SELL cancellations. CancelAll releases exactly.\n        yes_free = max(0.0, state.yes_inventory - sum(\n            o.remaining_quantity for o in state.own_orders if o.side == Side.SELL))\n        existing = {o.order_id: o for o in state.own_orders}\n        new_allocations = {}\n        out = []\n        for a in actions:\n            if isinstance(a, CancelAll):\n                free = state.cash\n                yes_free = state.yes_inventory\n                existing.clear()\n                new_allocations.clear()\n                out.append(a)\n            elif isinstance(a, CancelOrder):\n                o = existing.pop(a.order_id, None)\n                if o is not None and o.side == Side.BUY:\n                    free += o.remaining_quantity * o.price_ticks / 100.0\n                allocation = new_allocations.pop(a.order_id, None)\n                if allocation is not None:\n                    free += allocation[0]\n                    yes_free += allocation[1]\n                out.append(a)\n            elif isinstance(a, PlaceOrder):\n                p = a.price_ticks / 100.0\n                budget = max(0.0, free - reserve)\n                covered = 0.0 if a.side == Side.BUY else yes_free\n                unit = p if a.side == Side.BUY else 1.0 - p\n                q = quantize_down(min(a.quantity, covered + budget / unit), 0.01)\n                if q <= 0:\n                    continue\n                cover = min(q, covered)\n                cost = round((q - cover) * unit, 10)\n                free -= cost\n                yes_free -= cover\n                if a.client_order_id is not None:\n                    new_allocations[a.client_order_id] = (cost, cover)\n                out.append(a if q == a.quantity else PlaceOrder(\n                    a.side, a.price_ticks, q, a.client_order_id))\n            else:\n                out.append(a)\n        return out\n"
  },
  {
   "key": "f-side-exposure-cap",
   "code_sha256": "63a225267fe38bf106a17eeef6221c8aa4887a264be5cec32a5631331c326d4a",
   "assembled_sha256": "f8b84f0c94467a6a959490278f2054193546abb62afbd7964872cbe2f1c3de82",
   "code": "from orderbook_pm_challenge import BaseStrategy, CancelAll, CancelOrder, PlaceOrder, Side\n\nclass Strategy(_N):\n    CAP = 1.0\n    FORCE_OFF = False\n    OFF_MISMATCHES = 0\n    SPREAD_COUNTS = {1: 0, 2: 0, 3: 0, 4: 0}\n\n    def on_step(self, state):\n        original = list(super().on_step(state))\n        spread = getattr(self, \"s\", None)\n        active = not self.FORCE_OFF and spread in (1, 2, 3, 4)\n        if self.FORCE_OFF:\n            # Off-path equality is checked at every callback.\n            return original\n        if not active:\n            return original\n        type(self).SPREAD_COUNTS[spread] += 1\n        open_orders = {o.order_id: [o.side, o.price_ticks, o.remaining_quantity, True, None] for o in state.own_orders}\n        normalized = []\n        for index, action in enumerate(original):\n            if isinstance(action, CancelAll):\n                open_orders.clear()\n                normalized.append(action)\n            elif isinstance(action, CancelOrder):\n                open_orders.pop(action.order_id, None)\n                normalized.append(action)\n            elif isinstance(action, PlaceOrder):\n                key = action.client_order_id or (\"__new__\", index)\n                open_orders[key] = [action.side, action.price_ticks, float(action.quantity), False, index]\n                normalized.append(action)\n            else:\n                normalized.append(action)\n        limits = {\n            Side.BUY: max(0.0, float(state.cash)) * self.CAP,\n            Side.SELL: max(0.0, float(state.yes_inventory)) * self.CAP,\n        }\n        keep = set()\n        for side in (Side.BUY, Side.SELL):\n            rows = [(key, row) for key, row in open_orders.items() if row[0] == side]\n            rows.sort(key=lambda pair: (pair[1][1] if side == Side.SELL else -pair[1][1], pair[1][4] if pair[1][4] is not None else -1))\n            total = sum((row[1] / 100.0) * row[2] for _, row in rows)\n            while rows and total > limits[side] + 1e-9:\n                _, removed = rows.pop()\n                total -= (removed[1] / 100.0) * removed[2]\n            keep.update(key for key, _ in rows)\n        out = []\n        for action in normalized:\n            if isinstance(action, PlaceOrder):\n                key = action.client_order_id or next((k for k, row in open_orders.items() if row[4] == normalized.index(action)), None)\n                # Resolve duplicate-equal actions by original position below instead.\n                out.append(action)\n            else:\n                out.append(action)\n        # Rebuild action stream by identity/index so only retained new orders are submitted.\n        out = []\n        for index, action in enumerate(original):\n            if isinstance(action, PlaceOrder):\n                key = action.client_order_id or (\"__new__\", index)\n                if key in keep:\n                    out.append(action)\n            else:\n                out.append(action)\n        for key, row in open_orders.items():\n            if row[3] and key not in keep:\n                out.append(CancelOrder(key))\n        return out\n"
  },
  {
   "key": "f-phat-band-size",
   "code_sha256": "6011971e639d6f81baa48c08e3ee910641500b09b7bdbb3d744328bf612d91ac",
   "assembled_sha256": "608c1176ae3bf9cab74bdd39e59bc53b17f42b4737f86b13804e1e21d47e28a7",
   "code": "# Overlay f-phat-band-size: scale N's order sizes by probability band of the rival midpoint.\nfrom orderbook_pm_challenge.types import PlaceOrder, CancelAll, CancelOrder, Side\n\n\nclass Strategy(_N):\n    B_MID = 1.0   # size multiplier when rival mid is within [LO, HI] cents\n    B_EDGE = 1.0  # size multiplier outside the band\n    LO = 20.0\n    HI = 80.0\n    SPREADS = (1, 2, 3, 4)\n\n    def on_step(self, state):\n        acts = list(super().on_step(state))\n        if self.B_MID == 1.0 and self.B_EDGE == 1.0:\n            return acts\n        if getattr(self, \"s\", None) not in self.SPREADS:\n            return acts\n        bid = state.competitor_best_bid_ticks\n        ask = state.competitor_best_ask_ticks\n        if bid is not None and ask is not None:\n            mid = 0.5 * (bid + ask)\n        elif bid is not None:\n            mid = 99.0\n        elif ask is not None:\n            mid = 1.0\n        else:\n            return acts\n        b = self.B_MID if self.LO <= mid <= self.HI else self.B_EDGE\n        if b == 1.0:\n            return acts\n        # collateral budget: free cash plus what this step's cancels release\n        free = state.free_cash\n        own = {o.order_id: o for o in state.own_orders}\n        res = {}\n        avail_yes = max(0.0, state.yes_inventory)\n        for o in state.own_orders:\n            if o.side == Side.SELL:\n                avail_yes -= min(avail_yes, o.remaining_quantity)\n        out = []\n        placed = set()\n        for a in acts:\n            if isinstance(a, CancelAll):\n                free = state.cash\n                avail_yes = max(0.0, state.yes_inventory)\n                out.append(a)\n            elif isinstance(a, CancelOrder):\n                o = own.get(a.order_id)\n                if o is None and a.order_id not in placed:\n                    continue  # its placement was dropped by this overlay\n                if o is not None and o.side == Side.BUY:\n                    free += (o.price_ticks / 100.0) * o.remaining_quantity\n                out.append(a)\n            elif isinstance(a, PlaceOrder):\n                q = int(a.quantity * b * 100) / 100.0\n                p = a.price_ticks / 100.0\n                if a.side == Side.BUY:\n                    cost_per = p\n                    cov = 0.0\n                else:\n                    cov = min(q, avail_yes)\n                    cost_per = 1.0 - p\n                need = cost_per * (q - cov)\n                if need > free - 1e-6:\n                    q = cov + max(0.0, (free - 1e-6) / cost_per)\n                    q = int(q * 100) / 100.0\n                if q < 0.01:\n                    continue\n                if a.side == Side.SELL:\n                    cov = min(q, avail_yes)\n                    avail_yes -= cov\n                    free -= cost_per * (q - cov)\n                else:\n                    free -= cost_per * q\n                if a.client_order_id:\n                    placed.add(a.client_order_id)\n                out.append(PlaceOrder(a.side, a.price_ticks, q, a.client_order_id))\n            else:\n                out.append(a)\n        return out\n"
  }
 ],
 "notes": "9 blind overlay screens on N (sha256 bf0d179f3e47d28819f6fa7e0d25548c2ced43374c216d36460b00a26a26ffae). Every row's code re-hashed = code_sha256. Tuning 320000..320199, holdout 430000..430499, disjoint; finalist seeds untouched. No gain: all 9 overall holdout mean_diff <= 0. Top 3 by best per-spread mean_diff/se: cash-reserve-decay s3 +0.36se, side-exposure-cap s1 +0.31se, phat-band-size s1 +0.10se; none is a promotion signal. rival-inward-join is a no-op (0.0 on all 500 seeds; 87824/87829 joins rounded to zero size), ratio undefined, left out of top. Flagged: age-size-decay (h_n 497, 3 holdout collateral failures, incumbent_mean 94.53 vs 95.54), paired-size (134 collateral failures; item calls its scores invalid), fill-burst-pause (one development failure, holdout clean). order-count-cap notes a pre-guard failure (seed 320151) in prose only; not flagged. check_values: all 9 report 17.116002/20.017111/2.390311/241.484752 (seeds 310000..310003); agreement, not rerun here. incumbent_mean 95.5420 (holdout), 98.4707 (tuning) agree across complete rows. Plane source re-checks failed for cash-reserve-decay (1), rival-inward-join (2), phat-band-size (1), side-exposure-cap (1), age-size-decay (1); items carry no sources field, so not inspectable here. Numbers are local measurements, so rows stand; those items' provenance claims are unverified. Lesson: N's depth and sizes look near-optimal; cutting orders, exposure or size loses retail edge faster than it saves arbitrage loss."
}
```