{"approach": "m-safe: start strategy with only spread-3 a3-ledger block copied exactly; spreads 1, 2, 4 retain start blocks. Applied each supplied fix diff in descending listed gain within its spread, retaining only positive paired edge gains in both selection halves. No tuning or seed recognition.", "blocked": null, "base_mean_edge": 108.63974289615767, "exact": {"spread1": {"runs": 300, "identical": true}, "spread2": {"runs": 300, "identical": true}, "spread3": {"runs": 300, "identical": true}, "spread4": {"runs": 300, "identical": true}}, "fixes": [{"name": "a1-jumps", "kept": true, "gain": 0.8317693322811999, "standard_error": 0.35873561884138366}, {"name": "a1-free", "kept": false, "gain": 0.1623564006363998, "standard_error": 0.1415346551431088}, {"name": "a2-after", "kept": true, "gain": 1.0651422830891997, "standard_error": 0.17354929374259553}, {"name": "a2-ledger", "kept": true, "gain": 0.27792990249079996, "standard_error": 0.10146617507217796}, {"name": "a3-rich", "kept": true, "gain": 1.0785609271135999, "standard_error": 0.38144802285492224}, {"name": "a3-free", "kept": true, "gain": 0.26205756672299996, "standard_error": 0.0884205488779404}, {"name": "a4-rich", "kept": true, "gain": 0.5250457714106009, "standard_error": 0.10856922767315608}, {"name": "a4-free", "kept": true, "gain": 0.26696185971979836, "standard_error": 0.3000436788195861}, {"name": "a4-stock", "kept": true, "gain": 0.2542907039806001, "standard_error": 0.056770467549436286}], "by_spread": {"spread1": {"runs": 501, "mean": 0.8991263378299401, "standard_error": 0.3261258436241331, "retail": -0.26347085713692614, "arb": 1.1625971949544909}, "spread2": {"runs": 504, "mean": 0.965591594697817, "standard_error": 0.3381116020149563, "retail": -0.4783680687543645, "arb": 1.4439596634464285}, "spread3": {"runs": 479, "mean": 0.9424647366889358, "standard_error": 0.2238444848266483, "retail": -0.5412735746217119, "arb": 1.4837383113045928}, "spread4": {"runs": 516, "mean": 1.017723407602713, "standard_error": 0.21988715846672133, "retail": 0.26066379129709283, "arb": 0.757059616282558}}, "holdout": {"mean_edge": 94.4769774633412, "retail_edge": 118.4531573609182, "arb_edge": -23.97617989758095, "failures": 0}, "diff": {"mean": 0.95685317308875, "standard_error": 0.14141149083550503, "retail": -0.2489319660061499, "arb": 1.20578513908295}, "seconds": {"start": 46.43412822112441, "yours": 51.85971038695425}, "code": "\"\"\"Crossing-cover base with isolated, untuned per-spread overrides stacked: each acts only in runs of its own competitor spread.\"\"\"\nimport math\nfrom orderbook_pm_challenge.strategy import BaseStrategy\nfrom orderbook_pm_challenge.types import CancelOrder, PlaceOrder, Side\n\nP = dict(lam_r=0.25, m=5.0, sig_n=1.2, lam_j=0.0019, sig_j=0.35, sig=0.02,\n         qmax=3000.0, rmin=2, kA=0.7, kL=0.15, pL=0.05,\n         ammo=1.0, ydem=0.4, W=200.0, fy=0.6, ammo_q=60.0, ammo_pmax=0.05, ammo_maxpay=0.02,\n         fb=0.9, fu=0.7, xu=0.1, sticky=1.0, min_ahead=2.0, keep_hi=1.5, keep_lo=0.7, Hu=300.0, bins=8.0, filt=1.0, uni=0.01, jumpinfo=1.0, dmin=0.0, kLb=0.08, kLf=0.08, pinf=1.0, pre=0.0, H1=100.0,\n         ydf=0.6, Wf=2000.0, g_hi=0.15, g_lo=0.15, qf=400.0, pmaxf=0.05, pre_gap=1.0,\n         ydf1=0.6, g1=5.0, f1=0.6, a1=100.0, nb1=0.0, gs=1.0, p1t=1.0, m1=1.0, zd=1.0, pfl=0.0005)\nSQ2 = math.sqrt(2.0)\nSQ2PI = math.sqrt(2.0 * math.pi)\ndef cdf(x): return 0.5 * (1.0 + math.erf(x / SQ2))\ndef pdf(x): return math.exp(-0.5 * x * x) / SQ2PI\ndef inv(p):\n    p = min(max(p, 1e-9), 1 - 1e-9)\n    t = math.sqrt(-2.0 * math.log(min(p, 1 - p)))\n    x = t - (2.515517 + 0.802853 * t + 0.010328 * t * t) / (1 + 1.432788 * t + 0.189269 * t * t + 0.001308 * t ** 3)\n    x = -x if p < 0.5 else x\n    for _ in range(2):\n        d = pdf(x)\n        if d < 1e-12:\n            break\n        x -= (cdf(x) - p) / d\n    return x\ndef lpm(k):\n    return pdf(k) + k * cdf(k)\ndef fl(q):\n    return math.floor(q * 100 + 1e-9) / 100\n\nNODES = [(-2.2, .06), (-1.3, .17), (-0.6, .27), (0.6, .27), (1.3, .17), (2.2, .06)]\nPROBE = 0.01\n\n\nclass Strategy(BaseStrategy):\n    def __init__(self):\n        self.n = 0\n        self.ahead = set()     # main orders placed strictly ahead of any competitor order at their tick\n        self.res = {}          # order id -> uncovered quantity at placement\n        self.bc = None         # belief: sub-tick grid centres (ticks)\n        self.bw = None         # belief: weights\n        self.st = 0.5          # last one-step sd in ticks\n        self.pcb = self.pca = None\n        self.pb = set()\n        self.pa = set()\n        self.tb = 0\n        self.s = None          # competitor spread parameter\n        self.flow_notional = 0.0\n        self.flow_exposure = 0\n        self.last_ask_tick = None\n        self.last_quote_exposed = False\n        self.last_flow_ca = None\n        self.last_flow_cap = 0.0\n        self.last_flow_correction = 1.0\n        self.params = P.copy()\n        self.s2_mb = set()\n        self.s2_ma = set()\n        self.s2_lb = self.s2_la = -99\n\n    def _oid(self, tag):\n        self.n += 1\n        return tag + str(self.n)\n\n    def on_step(self, state):\n        H = max(1, state.steps_remaining)\n        cb = state.competitor_best_bid_ticks or 0\n        ca = state.competitor_best_ask_ticks or 100\n        if self.s is None:\n            self.s = max(1, (ca - cb + 1) // 2)\n            if self.s == 4:\n                # Use the existing low-price risk penalty on bids too; inventory\n                # cover orders already provide the separate stocking mechanism.\n                self.params['kLb'] = self.params['kLf'] = self.params['kL']\n                # Censored compound-Poisson flow likelihood, using only our fills.\n                self.f4_exposure = [0, 0]\n                self.f4_events = [0, 0]\n                self.f4_weights = [[0.0] * 9, [0.0] * 9]\n                self.f4_means = [2.64 + i * (6.336 - 2.64) / 8 for i in range(9)]\n                # Positive aggregate flow is approximately lognormal; +0.065\n                # accounts for the occasional second arrival in a timestep.\n                self.f4_mu = [math.log(m) - 0.72 + 0.065 for m in self.f4_means]\n                self.f4_last = [None, None]\n                self.f4_rate = 0.1265\n                self.f4_mean = 4.488\n                self.f4_flow = self.f4_rate * self.f4_mean\n                self.f4_extreme = inv(1 - 1e-6)\n            if self.s == 2:\n                self.params.update(dict(W=150, ammo_pmax=0.02, fy=0.7, fu=0.25, Hu=500))\n            if self.s == 1:\n                self.params.update({'dmin': 0.3, 'pfl': 1e-06})\n            if self.s == 3:\n                self.params.update({'flow_prior': 200, 'flow_level': 0.6, 'flow_strength': 1.0, 'flow_safety': 2.0, 'flow_exposure_min': 5.0})\n        P = self.params\n        if self.s == 4:\n            for side, filled, bound in ((0, state.sell_filled_quantity, ca), (1, state.buy_filled_quantity, cb)):\n                last = self.f4_last[side]\n                if last is None:\n                    continue\n                tick, conv, cap, old_bound, ids = last\n                if (side == 0 and bound > old_bound + 1) or (side == 1 and bound < old_bound - 1):\n                    continue\n                # Track only the main quote, excluding probes and stock orders.\n                remaining = sum(o.remaining_quantity for o in state.own_orders if o.order_id in ids)\n                value = max(0.0, cap - remaining * conv)\n                self.f4_exposure[side] += 1\n                if value > 0.01:\n                    self.f4_events[side] += 1\n                    censored = remaining < 0.011\n                    logv = math.log(max(value, 0.01))\n                    weights = self.f4_weights[side]\n                    for i, mu4 in enumerate(self.f4_mu):\n                        z4 = (logv - mu4) / 1.2\n                        weights[i] += math.log(max(1e-12, 1.0 - cdf(z4))) if censored else -0.5 * z4 * z4\n            if state.step % 25 == 0:\n                exposure = sum(self.f4_exposure)\n                events = sum(self.f4_events)\n                event_probability = (events + 80.0 * (1.0 - math.exp(-0.1265))) / (exposure + 80.0)\n                self.f4_rate = max(0.077, min(0.176, -math.log(max(1e-6, 1.0 - event_probability))))\n                weights = [a + b for a, b in zip(*self.f4_weights)]\n                peak = max(weights)\n                weights = [math.exp(w - peak) for w in weights]\n                self.f4_mean = sum(m * w for m, w in zip(self.f4_means, weights)) / sum(weights)\n                self.f4_flow = self.f4_rate * self.f4_mean\n        if self.s == 3 and self.last_quote_exposed and ca <= self.last_flow_ca + 1:\n            self.flow_exposure += 1\n            self.flow_notional += min(self.last_flow_cap, state.sell_filled_quantity * self.last_ask_tick / 100.0) * self.last_flow_correction\n        lo, hi = cb, ca\n        for o in state.own_orders:\n            if o.side is Side.BUY:\n                lo = max(lo, o.price_ticks)\n            else:\n                hi = min(hi, o.price_ticks)\n        if P['pinf'] > 0:\n            sb = {o.price_ticks for o in state.own_orders if o.side is Side.BUY and o.remaining_quantity <= PROBE + 1e-9}\n            sa = {o.price_ticks for o in state.own_orders if o.side is Side.SELL and o.remaining_quantity <= PROBE + 1e-9}\n            ea = self.pa - sa\n            eb = self.pb - sb\n            if sa and ea:\n                lo = max(lo, min(max(ea), hi))\n            if eb and (sb or min(eb) <= P['p1t']):\n                hi = min(hi, max(min(eb), lo))\n        if P['jumpinfo'] > 0 and self.pcb is not None:\n            if ca > self.pca + 1:\n                lo = max(lo, ca - 1)\n            if cb < self.pcb - 1:\n                hi = min(hi, cb + 1)\n        hitB = hitA = shB = shA = False\n        if self.s == 2:\n            ids = {o.order_id for o in state.own_orders}\n            hitB = bool(self.s2_mb) and not (self.s2_mb & ids)\n            hitA = bool(self.s2_ma) and not (self.s2_ma & ids)\n            if hitB:\n                self.s2_lb = state.step\n            if hitA:\n                self.s2_la = state.step\n            hitB = state.step - self.s2_lb < 1\n            hitA = state.step - self.s2_la < 1\n            if self.pcb is not None:\n                shB = cb < self.pcb - 1\n                shA = ca > self.pca + 1\n        self.pcb, self.pca = cb, ca\n        if lo > hi:\n            lo, hi = hi, lo\n        # sub-tick belief over p_(t-1): predict with one-step noise, truncate to [lo, hi]\n        wid = max(hi - lo, 1e-6)\n        nb = max(2, min(48, int(round(wid * P['bins']))))\n        cs = [lo + (i + 0.5) * wid / nb for i in range(nb)]\n        if self.bc is None or P['filt'] <= 0:\n            ws = [1.0 / nb] * nb\n        else:\n            sg = max(self.st, 0.6 * wid / nb)\n            k = -0.5 / (sg * sg)\n            ws = []\n            uni = P['uni'] * sg\n            if self.s == 4:\n                exp = math.exp\n                if self.bc == cs and 1.0 <= wid <= 6.0 and nb == 8 * wid:\n                    # On this stationary grid, spacing is exactly 1/8 tick.\n                    # Equal index distances therefore have bit-identical d*d*k.\n                    # Reuse exp values while retaining the original sum order.\n                    kernel = []\n                    c0 = cs[0]\n                    for ci in self.bc:\n                        d = c0 - ci\n                        d2 = d * d * k\n                        kernel.append(exp(d2) if d2 > -12.5 else 0.0)\n                    kernel = kernel[:0:-1] + kernel\n                    for i in range(nb):\n                        t = uni\n                        start = nb - 1 - i\n                        for wi, e in zip(self.bw, kernel[start:start + nb]):\n                            if e:\n                                t += wi * e\n                        ws.append(t)\n                else:\n                    previous = tuple(zip(self.bc, self.bw))\n                    for c in cs:\n                        t = uni\n                        for ci, wi in previous:\n                            d = c - ci\n                            d2 = d * d * k\n                            if d2 > -12.5:\n                                t += wi * exp(d2)\n                        ws.append(t)\n            else:\n                for c in cs:\n                    t = uni\n                    for ci, wi in zip(self.bc, self.bw):\n                        d = c - ci\n                        d2 = d * d * k\n                        if d2 > -12.5:\n                            t += wi * math.exp(d2)\n                    ws.append(t)\n            tot = sum(ws)\n            ws = [w / tot for w in ws]\n        self.bc, self.bw = cs, ws\n        mean_t = sum(c * w for c, w in zip(cs, ws))\n        var_t = max(sum(c * c * w for c, w in zip(cs, ws)) - mean_t * mean_t, 0.0)\n        phat = min(max(mean_t / 100.0, 0.002), 0.998)\n        var = P['sig'] ** 2 + P['lam_j'] * P['sig_j'] ** 2\n        sd = math.sqrt(H * var)\n        self.tb = self.tb + 1 if hi <= 1 else 0\n        if self.tb > 0 and P['zd'] > 0:\n            # below the last tick there is no probe: the score keeps walking away from it\n            phat = min(phat, max(P['pfl'], cdf(inv(0.01) - P['zd'] * 0.02 * math.sqrt(self.tb) / sd)))\n        z = inv(phat)\n        Z = z * sd\n        sp = pdf(z) / sd * P['sig']\n        self.st = sp * 100.0\n        s = math.sqrt(sp * sp + var_t / 1e4 + 1e-8)\n        sd1 = math.sqrt(max(1.0, H - 1.0) * var)\n        jp = [(cdf((Z + n * P['sig_j']) / sd1), w) for n, w in NODES]\n        lj = P['lam_j']\n\n        def AB(x):\n            k = (x - phat) / s\n            a = s * lpm(k)\n            b = a - (x - phat)\n            if self.s == 4:\n                ja = jb = 0.0\n                for p, w in jp:\n                    if x > p:\n                        ja += w * (x - p)\n                    else:\n                        jb += w * (p - x)\n            else:\n                ja = sum(w * max(0.0, x - p) for p, w in jp)\n                jb = sum(w * max(0.0, p - x) for p, w in jp)\n            return (1 - lj) * a + lj * ja, (1 - lj) * b + lj * jb\n\n        if H == 1:\n            def AB(x):\n                return (1 - phat) * x, phat * (1 - x)\n        rho = P['lam_r'] * 0.5\n        mu = math.log(P['m']) - 0.5 * P['sig_n'] ** 2\n        kA = P['kL'] if phat < P['pL'] else P['kA']\n\n        def qsize(loss, gain, px):\n            loss *= kA\n            if gain <= 0:\n                return 0.0\n            tail = loss / (rho * gain)\n            if tail >= 1.0:\n                return 0.0\n            if self.s == 4 and tail <= 1e-6:\n                return min(P['qmax'], math.exp(mu + P['sig_n'] * self.f4_extreme) / px)\n            return min(P['qmax'], math.exp(mu + P['sig_n'] * inv(1 - max(tail, 1e-6))) / px)\n\n        ptk = phat * 100\n        def qbid(t):\n            if not 1 <= t <= 99:\n                return 0.0\n            if self.s == 4 and phat * 100 - t < P['dmin']:\n                return 0.0\n            a, b = AB(t / 100.0)\n            if phat * 100 - t < P['dmin']:\n                return 0.0\n            if P['nb1'] > 0 and self.s == 1 and t == 1 and ptk < 1.0:\n                return 0.0\n            if phat < P['pL']:\n                ytg = P['ydem'] * min(H, P['W']) / max(ca - 1, ptk + 1) * 100.0\n                a *= (P['kLb'] if state.yes_inventory < ytg else P['kLf']) / P['kL']\n                if self.s == 3:\n                    # Subsidize cover only while more stock is needed for remaining retail.\n                    # Once the whole horizon is covered, use the ordinary bid risk weight.\n                    flow = (self.flow_notional + P['flow_prior'] * P['flow_level']) / (P['flow_prior'] + self.flow_exposure)\n                    if state.yes_inventory >= flow * H / max(ca - 1, ptk + 1) * 100.0:\n                        a *= P['kA'] / P['kLf']\n            return qsize(a, b, max(phat, 0.05))\n\n        def qask(t):\n            if not 1 <= t <= 99:\n                return 0.0\n            if self.s == 4 and t - phat * 100 < P['dmin']:\n                return 0.0\n            a, b = AB(t / 100.0)\n            if t - phat * 100 < P['dmin']:\n                return 0.0\n            if self.s == 4:\n                tail = b * kA / max(self.f4_rate * a, 1e-30)\n                if a <= 0 or tail >= 1.0:\n                    return 0.0\n                return min(P['qmax'], math.exp(math.log(self.f4_mean) - 0.72 + 1.2 * (self.f4_extreme if tail <= 1e-6 else inv(1 - tail))) / (t / 100.0))\n            if self.s == 2 and phat < 0.1:\n                a = max(0.0, a - 0.0015 * (1 - min(1.0, state.yes_inventory / 3000.0)))\n            return qsize(b, a, t / 100.0)\n\n        bids = [o for o in state.own_orders if o.side is Side.BUY and o.remaining_quantity > PROBE + 1e-9]\n        asks = [o for o in state.own_orders if o.side is Side.SELL and o.remaining_quantity > PROBE + 1e-9]\n        sticky = P['sticky'] > 0\n        def top(orders, comp, step):\n            threshold = max(P['min_ahead'], 20 * 100.0 / comp) if self.s == 3 and step == -1 and 1 <= comp <= 5 else P['min_ahead']\n            if sticky and sum(o.remaining_quantity for o in orders if o.price_ticks == comp and o.order_id in self.ahead) >= threshold:\n                return comp\n            return comp + step\n        bid_t = top(bids, cb, 1)\n        ask_t = top(asks, ca, -1)\n        qb = qbid(bid_t)\n        qa = qask(ask_t)\n        if self.s == 1 and ask_t == 2 and ask_t < ca and phat < 0.01:\n            qa *= 5\n\n        Y = state.yes_inventory\n        if ask_t == 1 and H > P['H1'] and P['pre'] > 0:\n            qa = qa if Y >= P['a1'] > 0 else 0.0          # let the competitor's 2-tick ask erode instead of fronting it for nothing\n        # ammunition: hold YES so that low asks are covered\n        ptick = phat * 100\n        amt = 0\n        qam = 0.0\n        if P['ammo'] > 0 and ask_t >= 2 and phat < max(P['ammo_pmax'], P['pmaxf']):\n            wealth = state.cash + Y * phat\n            x = max(ask_t, ptick + 1) / 100.0\n            capw = P['fy'] * wealth / max(phat, 0.005)\n            flow_scale = self.f4_flow / 0.6 if self.s == 4 else 1.0\n            target = min(flow_scale * P['ydem'] * min(H, P['W']) / x, capw)\n            if self.s == 3:\n                # Buy routine cover only for the current front ask's desired size.\n                target = min(target, qa)\n            if self.s == 4:\n                # Pay above fair value only for the current retail quote's cover.\n                target = min(target, qa)\n            full = min(flow_scale * P['ydf'] * min(H, P['Wf']) / x, capw) if phat < P['pmaxf'] else 0.0\n            t = max(1, min(99, int(math.ceil(ptick + 1e-9))))\n            g = t - ptick\n            if self.s != 3 and Y < full and g <= P['g_hi'] and bid_t <= t < ask_t:\n                amt, qam = t, min(P['qf'], full - Y)     # a tick p has just crossed: nearly free\n            elif (self.s != 2 or t == 1) and Y < target and phat < P['ammo_pmax'] and bid_t <= t < ask_t and t / 100.0 - phat < P['ammo_maxpay']:\n                amt, qam = t, min(P['ammo_q'], target - Y)\n            elif Y < full and t >= 2 and 1.0 - g <= P['g_lo']:\n                amt, qam = t - 1, min(P['qf'], full - Y)  # rest just under p: filled only on the crossing, or by retail\n\n        if P['pre'] > 0 and ca == 2 and phat < 0.01 and H > P['H1'] and Y < P['pre'] and not qam and 1.0 - ptick < P['pre_gap']:\n            amt, qam = 1, min(P['ammo_q'], P['pre'] - Y)\n        q1 = 0.0\n        if P['ydf1'] > 0 and P['m1'] < ptick < P['g1'] + 1.0 and amt != 1:\n            stock_rate = P['ydf1']\n            if self.s == 4:\n                stock_rate *= self.f4_flow / 0.6\n            if self.s == 3:\n                flow = (self.flow_notional + P['flow_prior'] * P['flow_level']) / (P['flow_prior'] + self.flow_exposure)\n                scale = max(0.5, min(2.0, flow / P['flow_level']))\n                stock_rate *= 1.0 + P['flow_strength'] * (scale - 1.0)\n            q1 = max(0.0, stock_rate * min(H, P['Wf']) / (self.s / 100.0) - Y)\n\n        # Bridge expected retail demand until another tick crossing is available.\n        if 0.02 < phat < 0.1:\n            ct = max(2, min(99, int(math.floor(ptick))))\n            wealth = state.cash + Y * phat\n            goal = min(1 * qa, 0.3 * max(wealth, 0.0) / phat)\n            if Y < goal and ct < ask_t:\n                amt, qam = ct, min(3000.0, goal - Y)\n        if self.s == 2:\n            if hitB:\n                qb = 0.0\n                qam = 0.0\n                q1 = 0.0\n            if hitA:\n                qa = 0.0\n        # order management\n        actions = []\n        free = state.free_cash - 2.0\n        keep_ask = 0.0\n        new_b = []\n        new_a = []\n        def cancel(o):\n            nonlocal free\n            actions.append(CancelOrder(o.order_id))\n            x = o.price_ticks / 100.0\n            if o.side is Side.BUY:\n                free += x * o.remaining_quantity\n            else:\n                free += (1 - x) * min(self.res.get(o.order_id, 0.0), o.remaining_quantity)\n            self.ahead.discard(o.order_id)\n            self.res.pop(o.order_id, None)\n        for o in state.own_orders:\n            if o.remaining_quantity <= PROBE + 1e-9:\n                cancel(o)\n        kept_ids = set()\n        def manage(orders, t, q, comp):\n            kept = 0.0\n            for o in orders:\n                if o.price_ticks == t and q > 0 and (kept + o.remaining_quantity <= max(q * P['keep_hi'], 1.0) or (self.s == 1 and (o.side is Side.SELL) and o.price_ticks <= 2 and o.order_id in self.ahead)):\n                    kept += o.remaining_quantity\n                    kept_ids.add(o.order_id)\n                else:\n                    cancel(o)\n            return kept\n        kb = manage(bids, bid_t, qb, cb)\n        ka = manage(asks, ask_t, qa, ca)\n        add_b = (qb - kb) if (kb < qb * P['keep_lo'] and bid_t != cb) else 0.0\n        add_a = (qa - ka) if (ka < qa * P['keep_lo'] and ask_t != ca) else 0.0\n\n        budget = P['fb'] * max(free, 0.0)\n        cost = add_b * bid_t / 100.0 + qam * amt / 100.0\n        if cost > budget:\n            f = budget / cost\n            add_b *= f\n            qam *= f\n            cost = budget\n        out = []\n        q1 = min(q1, P['f1'] * max(budget - cost, 0.0) * 100.0)\n        if q1 >= 0.01:\n            out.append(PlaceOrder(side=Side.BUY, price_ticks=1, quantity=fl(q1)))\n            free -= fl(q1) / 100.0 + 1e-6\n        if amt and qam >= 0.01:\n            q = fl(qam)\n            out.append(PlaceOrder(side=Side.BUY, price_ticks=amt, quantity=q))\n            free -= q * amt / 100.0 + 1e-6\n        if bid_t >= 1 and add_b >= 0.01:\n            q = fl(add_b)\n            oid = self._oid('b')\n            out.append(PlaceOrder(side=Side.BUY, price_ticks=bid_t, quantity=q, client_order_id=oid))\n            free -= q * bid_t / 100.0 + 1e-6\n            if bid_t > cb:\n                self.ahead.add(oid)\n        if ask_t <= 99 and add_a >= 0.01:\n            x = ask_t / 100.0\n            covk = sum(o.remaining_quantity - min(self.res.get(o.order_id, 0.0), o.remaining_quantity)\n                       for o in asks if o.order_id in kept_ids)\n            cov = max(0.0, Y - covk - 0.1)\n            unc = max(0.0, add_a - cov)\n            if unc > 0:\n                ub = max(0.0, free - (1 - P['fu']) * max(state.cash, 0.0)) if x >= P['xu'] else 0.0\n                if H < P['Hu'] and phat < 0.05:\n                    ub = max(0.0, free * (1 - H / P['Hu']))\n                if self.s == 2:\n                    ub = min(ub, max(0.0, free - 200 * min(1.0, H / 50.0)))\n                unc = min(unc, ub / (1 - x))\n            q = fl(min(add_a, cov + unc))\n            if q >= 0.01:\n                oid = self._oid('a')\n                out.append(PlaceOrder(side=Side.SELL, price_ticks=ask_t, quantity=q, client_order_id=oid))\n                r = max(0.0, q - cov)\n                self.res[oid] = r\n                free -= r * (1 - x) + 1e-6\n                if ask_t < ca:\n                    self.ahead.add(oid)\n\n        # probes: tiny orders that the arbitrageur removes when p crosses them\n        f = int(math.floor(ptick + 1e-9))\n        r = max(int(P['rmin']), int(math.ceil(2.0 * s * 100)))\n        self.pb = set()\n        self.pa = set()\n        if free > 1.0:\n            for t in range(f, f + r + 1):\n                if cb < t < ca and 1 <= t <= 99:\n                    out.append(PlaceOrder(side=Side.BUY, price_ticks=t, quantity=PROBE))\n                    self.pb.add(t)\n            for t in range(f + 1 - r, f + 2):\n                if cb < t < ca and 1 <= t <= 99:\n                    out.append(PlaceOrder(side=Side.SELL, price_ticks=t, quantity=PROBE))\n                    self.pa.add(t)\n            if self.s == 4:\n                # Resting probes between p's tick and each main quote: the arbitrageur leaves them\n                # unless p crosses, so a crossing is still located when retail clears the other side.\n                for t in range(max(cb, bid_t) + 1, f):\n                    if t < ca and 1 <= t <= 99:\n                        out.append(PlaceOrder(side=Side.BUY, price_ticks=t, quantity=PROBE))\n                        self.pb.add(t)\n                for t in range(f + 2, min(ca, ask_t)):\n                    if t > cb and 1 <= t <= 99:\n                        out.append(PlaceOrder(side=Side.SELL, price_ticks=t, quantity=PROBE))\n                        self.pa.add(t)\n        if self.s == 3:\n            self.last_ask_tick = ask_t\n            self.last_flow_ca = ca\n            exposed_qty = ka + sum(o.quantity for o in out if o.side is Side.SELL and o.price_ticks == ask_t and o.quantity > PROBE)\n            self.last_flow_cap = exposed_qty * ask_t / 100.0\n            self.last_quote_exposed = ask_t / 100.0 > phat + max(0.005, P['flow_safety'] * self.st / 100.0) and self.last_flow_cap >= P['flow_exposure_min']\n            if self.last_quote_exposed:\n                logcap = math.log(self.last_flow_cap)\n                mu_flow = math.log(P['m']) - 0.5 * P['sig_n'] ** 2\n                clipped = P['m'] * cdf((logcap - mu_flow - P['sig_n'] ** 2) / P['sig_n']) + self.last_flow_cap * (1.0 - cdf((logcap - mu_flow) / P['sig_n']))\n                self.last_flow_correction = min(3.0, P['m'] / max(clipped, 0.01))\n        if self.s == 4:\n            self.f4_last = [None, None]\n            # Eligibility is decided before observing fills, so depleted quotes\n            # remain in the sample as right-censored observations.\n            for side, tick, bound, conv, distance in (\n                (0, ask_t, ca, ask_t / 100.0, ask_t / 100.0 - phat),\n                (1, bid_t, cb, max(phat, 0.05), phat - bid_t / 100.0)):\n                if distance < max(0.01, 3.0 * self.st / 100.0):\n                    continue\n                if side == 0:\n                    if not (ask_t < ca or any(o.price_ticks == ask_t and o.order_id in self.ahead for o in asks)):\n                        continue\n                    orders = asks\n                    order_side = Side.SELL\n                else:\n                    if not (bid_t > cb or any(o.price_ticks == bid_t and o.order_id in self.ahead for o in bids)):\n                        continue\n                    if (qam > 0 and amt >= bid_t) or (q1 > 0 and bid_t <= 1):\n                        continue\n                    orders = bids\n                    order_side = Side.BUY\n                tracked = {o.order_id: o.remaining_quantity for o in orders if o.order_id in kept_ids and o.price_ticks == tick}\n                tracked.update({o.client_order_id: o.quantity for o in out if o.side is order_side and o.price_ticks == tick and o.client_order_id is not None})\n                cap = sum(tracked.values()) * conv\n                if cap >= 0.5:\n                    self.f4_last[side] = (tick, conv, cap, bound, tracked)\n        if self.s == 1:\n            split_out = []\n            for order in out:\n                oid = order.client_order_id\n                if (order.side is Side.SELL and oid is not None and oid.startswith('a')\n                        and order.price_ticks >= 3 and order.price_ticks < 99):\n                    back = fl(order.quantity * 0.5)\n                    front = fl(order.quantity - back)\n                    reserve = self.res.pop(oid, 0.0)\n                    front_reserve = max(0.0, reserve - back)\n                    if front >= 0.01:\n                        split_out.append(PlaceOrder(side=Side.SELL, price_ticks=order.price_ticks, quantity=front, client_order_id=oid))\n                        self.res[oid] = front_reserve\n                    if back >= 0.01:\n                        back_id = self._oid('a')\n                        split_out.append(PlaceOrder(side=Side.SELL, price_ticks=order.price_ticks + 1, quantity=back, client_order_id=back_id))\n                        self.res[back_id] = max(0.0, reserve-front_reserve)\n                else:\n                    split_out.append(order)\n            out = split_out\n        if self.s == 2:\n            self.s2_mb = {o.order_id for o in bids if o.order_id in kept_ids} | {o.client_order_id for o in out if o.side is Side.BUY and o.client_order_id}\n            self.s2_ma = {o.order_id for o in asks if o.order_id in kept_ids} | {o.client_order_id for o in out if o.side is Side.SELL and o.client_order_id}\n        return actions + out\n", "code_sha256": "f43e55003da486ec97ef2a8c102a430a08d648a4504efbbabcf157dc47eb83ab", "tried": ["Scorer CLI: 600 seeds 1000..1599, --workers 4, no sandbox; 1247.91 seconds; simulator b244530ee2a6247b5f930830eeca9dd950da0e7e.", "Run-count divisor 2: baseline exceeded five minutes; halved subsequent counts.", "Validation runtime: 3.12.15 (d90944c94ad6, Oct 13 2026, 18:01:21) [PyPy 8.0.1 with GCC 14.2.1 20250110 (Red Hat 14.2.1-11)]; strategy and simulator source unmodified except the specified merges/fixes.", "Cross-runtime smoke check, earlier strategy seed 1000: tiny differences in initial probability and inventory averages; no CPython bit-parity claim.", "Full SimulationResult dictionaries equal in both exactness windows for each spread; source spread3=a3-ledger, others=start.", "a1-jumps: paired 500 spread-1 seeds selected from 120000; first-half gain 0.7687271797132001, second-half 0.8948114848491997; kept.", "a1-free: paired 500 spread-1 seeds selected from 120000; first-half gain 0.3717214736231996, second-half -0.047008672350399995; dropped.", "a2-after: paired 500 spread-2 seeds selected from 120000; first-half gain 0.9105394489799995, second-half 1.2197451171984; kept.", "a2-ledger: paired 500 spread-2 seeds selected from 120000; first-half gain 0.20195569103680017, second-half 0.3539041139447997; kept.", "a3-rich: paired 500 spread-3 seeds selected from 120000; first-half gain 0.6189212924428005, second-half 1.5382005617843995; kept.", "a3-free: paired 500 spread-3 seeds selected from 120000; first-half gain 0.13449495899799924, second-half 0.3896201744480007; kept.", "a4-rich: paired 500 spread-4 seeds selected from 120000; first-half gain 0.6058425435452005, second-half 0.4442489992760013; kept.", "a4-free: paired 500 spread-4 seeds selected from 120000; first-half gain 0.019287730081598512, second-half 0.5146359893579981; kept.", "a4-stock: paired 500 spread-4 seeds selected from 120000; first-half gain 0.29487897240759997, second-half 0.21370243555360022; kept.", "Frozen holdout: contiguous seeds 130000..131999; all paired; timing: 100 timed runs of each strategy in the same persistent holdout worker; includes result conversion; strategy module load excluded; seeds 130000..130099.", "All nine supplied fix diffs were portable; none was rewritten or dropped for a merge conflict. Only the supplied block and fixes changed the strategy.", "The required CPython scorer exceeded five minutes before the alternative-runtime trials began. Redundant experimental PyPy scorer attempts were stopped; their unfinished results were not used. Validation resumed from completed batches when per-10-run checkpoints were added.", "Re-fetched all 20 source URLs and verified every quoted passage. Validated final JSON schema, 2000 paired holdout seeds, all exactness counts, strategy syntax, SHA-256, and output byte limit."], "next": "Operator submits code by hand; no key needed. Fix selection uses only seeds selected from 120000; frozen evaluation uses independent seeds from 130000. Standard errors are sample SD of paired per-run total-edge differences divided by sqrt(n). Timing is total wall seconds for each serial batch, not per run. No older-base blocks used. Exactness, fix selection, holdout metrics and timing use PyPy 3.12.15; the reference scorer uses CPython 3.12.3. A cross-runtime smoke test showed small floating-point differences, so exactness here compares both strategies within PyPy and does not establish CPython bit parity. All post-reference run counts were halved as instructed."}