{"abstract":"Large rank gaps produce impossible handicaps.","category":"Go territory scoring","checks":8,"contract":"Input [rank_a, rank_b] as Nk (1..30) or Nd (1..9); 1k and 1d are one rank apart. Equal ranks -> [rank_a, 0, 65]; one rank apart -> [weaker, 0, 5]; otherwise [weaker, min(diff, 9), 5]. Invalid ranks -> \"invalid\". The first element is the player taking black.","contract_signature":"x","evaluation_group":"w2-go-territory-scoring-rank-handicap","failed_approach":"Subtracting one from the rank gap under-handicaps every game.","family":"w2-go-territory-scoring-rank-handicap-stone-cap","id":"FA-83211","implementations":{"attempt":{"sha256":"6344beab2be31f7951349461fa0e249d1ed2facb5223b877e9cab2bd00de07a1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    def val(s):\n        if len(s) < 2 or not s[:-1].isdigit():\n            return None\n        k = int(s[:-1])\n        if s[-1] == 'k' and 1 <= k <= 30:\n            return 1 - k\n        if s[-1] == 'd' and 1 <= k <= 9:\n            return k\n        return None\n    a, b = x\n    va, vb = val(a), val(b)\n    if va is None or vb is None:\n        return 'invalid'\n    diff = abs(va - vb)\n    weaker = a if va < vb else b\n    if diff == 0:\n        return [a, 0, 65]\n    if diff == 1:\n        return [weaker, 0, 5]\n    return [weaker, min(diff - 1, 9), 5]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[['30k', '3k'], ['30k', 9, 5]], [['20k', '2d'], ['20k', 9, 5]], [['20k', '5d'], ['20k', 9, 5]], [['20k', '9d'], ['20k', 9, 5]], [['20k', '3p'], 'invalid'], [['10k', '5k'], ['10k', 5, 5]], [['10k', 'k'], 'invalid'], [['2k', '10k'], ['10k', 8, 5]]], [[['20k', '1k'], ['20k', 9, 5]], [['10k', '6d'], ['10k', 9, 5]], [['5k', '1k'], ['5k', 4, 5]], [['5k', '0k'], 'invalid'], [['5k', 'k'], 'invalid'], [['3k', '2d'], ['3k', 4, 5]], [['3k', '3d'], ['3k', 5, 5]], [['1k', '5d'], ['1k', 5, 5]]], [[['20k', '5d'], ['20k', 9, 5]], [['3k', '9d'], ['3k', 9, 5]], [['3k', '0k'], 'invalid'], [['2k', '30k'], ['30k', 9, 5]], [['2k', '10k'], ['10k', 8, 5]], [['2k', '1d'], ['2k', 2, 5]], [['2k', '3d'], ['2k', 4, 5]], [['1d', '6d'], ['1d', 5, 5]]], [[['3k', '9d'], ['3k', 9, 5]], [['1k', '3k'], ['3k', 2, 5]], [['1k', '2k'], ['2k', 0, 5]], [['1k', '1k'], ['1k', 0, 65]], [['1k', '5d'], ['1k', 5, 5]], [['1k', '9d'], ['1k', 9, 5]], [['1k', '0k'], 'invalid'], [['3d', '4k'], ['4k', 6, 5]]], [[['1k', '8k'], ['8k', 7, 5]], [['1d', '30k'], ['30k', 9, 5]], [['1d', '20k'], ['20k', 9, 5]], [['1d', '2k'], ['2k', 2, 5]], [['1d', '8k'], ['8k', 8, 5]], [['1d', '6d'], ['1d', 5, 5]], [['1d', '4k'], ['4k', 4, 5]], [['12k', '20k'], ['20k', 8, 5]]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"handicap case %d\" % i, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"c93d2c6f571917f24fc113f104721eb788c38f1584cd5d97362f98a90cef6f46","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    def val(s):\n        if len(s) < 2 or not s[:-1].isdigit():\n            return None\n        k = int(s[:-1])\n        if s[-1] == 'k' and 1 <= k <= 30:\n            return 1 - k\n        if s[-1] == 'd' and 1 <= k <= 9:\n            return k\n        return None\n    a, b = x\n    va, vb = val(a), val(b)\n    if va is None or vb is None:\n        return 'invalid'\n    diff = abs(va - vb)\n    weaker = a if va < vb else b\n    if diff == 0:\n        return [a, 0, 65]\n    if diff == 1:\n        return [weaker, 0, 5]\n    return [weaker, diff, 5]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[['30k', '3k'], ['30k', 9, 5]], [['20k', '2d'], ['20k', 9, 5]], [['20k', '5d'], ['20k', 9, 5]], [['20k', '9d'], ['20k', 9, 5]], [['20k', '3p'], 'invalid'], [['10k', '5k'], ['10k', 5, 5]], [['10k', 'k'], 'invalid'], [['2k', '10k'], ['10k', 8, 5]]], [[['20k', '1k'], ['20k', 9, 5]], [['10k', '6d'], ['10k', 9, 5]], [['5k', '1k'], ['5k', 4, 5]], [['5k', '0k'], 'invalid'], [['5k', 'k'], 'invalid'], [['3k', '2d'], ['3k', 4, 5]], [['3k', '3d'], ['3k', 5, 5]], [['1k', '5d'], ['1k', 5, 5]]], [[['20k', '5d'], ['20k', 9, 5]], [['3k', '9d'], ['3k', 9, 5]], [['3k', '0k'], 'invalid'], [['2k', '30k'], ['30k', 9, 5]], [['2k', '10k'], ['10k', 8, 5]], [['2k', '1d'], ['2k', 2, 5]], [['2k', '3d'], ['2k', 4, 5]], [['1d', '6d'], ['1d', 5, 5]]], [[['3k', '9d'], ['3k', 9, 5]], [['1k', '3k'], ['3k', 2, 5]], [['1k', '2k'], ['2k', 0, 5]], [['1k', '1k'], ['1k', 0, 65]], [['1k', '5d'], ['1k', 5, 5]], [['1k', '9d'], ['1k', 9, 5]], [['1k', '0k'], 'invalid'], [['3d', '4k'], ['4k', 6, 5]]], [[['1k', '8k'], ['8k', 7, 5]], [['1d', '30k'], ['30k', 9, 5]], [['1d', '20k'], ['20k', 9, 5]], [['1d', '2k'], ['2k', 2, 5]], [['1d', '8k'], ['8k', 8, 5]], [['1d', '6d'], ['1d', 5, 5]], [['1d', '4k'], ['4k', 4, 5]], [['12k', '20k'], ['20k', 8, 5]]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"handicap case %d\" % i, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Small rectangular toy boards given as strings of B, W and dot; a bounded teaching model of one scoring or bookkeeping rule, not a complete rules engine or server implementation. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-go-territory-scoring-rank-handicap-stone-cap","generated_at":"2026-09-29T14:50:19.410558+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Go servers and scoring tools compute this value automatically; a wrong answer changes a game result.","root_cause":"The stone count is not capped.","sha256":"e1ad718d6483d7341e8fea6d05e92c22b3d69b47b54e7f45a719771cc39884f0","title":"Handicap exceeds nine stones · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.036,"exit_code":1,"observations":[{"actual":["30k",9,5],"check":"handicap case 0","expected":["30k",9,5],"passed":true},{"actual":["20k",9,5],"check":"handicap case 1","expected":["20k",9,5],"passed":true},{"actual":["20k",9,5],"check":"handicap case 2","expected":["20k",9,5],"passed":true},{"actual":["20k",9,5],"check":"handicap case 3","expected":["20k",9,5],"passed":true},{"actual":"invalid","check":"handicap case 4","expected":"invalid","passed":true},{"actual":["10k",4,5],"check":"handicap case 5","expected":["10k",5,5],"passed":false},{"actual":"invalid","check":"handicap case 6","expected":"invalid","passed":true},{"actual":["10k",7,5],"check":"handicap case 7","expected":["10k",8,5],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"handicap case 0\", \"actual\": [\"30k\", 9, 5], \"expected\": [\"30k\", 9, 5], \"passed\": true}, {\"check\": \"handicap case 1\", \"actual\": [\"20k\", 9, 5], \"expected\": [\"20k\", 9, 5], \"passed\": true}, {\"check\": \"handicap case 2\", \"actual\": [\"20k\", 9, 5], \"expected\": [\"20k\", 9, 5], \"passed\": true}, {\"check\": \"handicap case 3\", \"actual\": [\"20k\", 9, 5], \"expected\": [\"20k\", 9, 5], \"passed\": true}, {\"check\": \"handicap case 4\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"handicap case 5\", \"actual\": [\"10k\", 4, 5], \"expected\": [\"10k\", 5, 5], \"passed\": false}, {\"check\": \"handicap case 6\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"handicap case 7\", \"actual\": [\"10k\", 7, 5], \"expected\": [\"10k\", 8, 5], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.894,"exit_code":1,"observations":[{"actual":["30k",27,5],"check":"handicap case 0","expected":["30k",9,5],"passed":false},{"actual":["20k",21,5],"check":"handicap case 1","expected":["20k",9,5],"passed":false},{"actual":["20k",24,5],"check":"handicap case 2","expected":["20k",9,5],"passed":false},{"actual":["20k",28,5],"check":"handicap case 3","expected":["20k",9,5],"passed":false},{"actual":"invalid","check":"handicap case 4","expected":"invalid","passed":true},{"actual":["10k",5,5],"check":"handicap case 5","expected":["10k",5,5],"passed":true},{"actual":"invalid","check":"handicap case 6","expected":"invalid","passed":true},{"actual":["10k",8,5],"check":"handicap case 7","expected":["10k",8,5],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"handicap case 0\", \"actual\": [\"30k\", 27, 5], \"expected\": [\"30k\", 9, 5], \"passed\": false}, {\"check\": \"handicap case 1\", \"actual\": [\"20k\", 21, 5], \"expected\": [\"20k\", 9, 5], \"passed\": false}, {\"check\": \"handicap case 2\", \"actual\": [\"20k\", 24, 5], \"expected\": [\"20k\", 9, 5], \"passed\": false}, {\"check\": \"handicap case 3\", \"actual\": [\"20k\", 28, 5], \"expected\": [\"20k\", 9, 5], \"passed\": false}, {\"check\": \"handicap case 4\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"handicap case 5\", \"actual\": [\"10k\", 5, 5], \"expected\": [\"10k\", 5, 5], \"passed\": true}, {\"check\": \"handicap case 6\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"handicap case 7\", \"actual\": [\"10k\", 8, 5], \"expected\": [\"10k\", 8, 5], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}