{"abstract":"A 10x10 board with 5+ handicap gets off-centre \"tengen\" stones.","category":"Go territory scoring","checks":8,"contract":"Input [size, count]. Star line e = 2 (0-based) below 13x13 else 3; f = size-1-e; mid = size//2. Counts outside 2..9 give []. Even boards allow at most 4. Order: [e,f],[f,e],[f,f],[e,e]; counts 6-9 add [mid,e],[mid,f]; 8-9 add [e,mid],[f,mid]; odd counts from 5 add the centre last.","contract_signature":"x","evaluation_group":"w2-go-territory-scoring-handicap-points","failed_approach":"Guarding only centre counts still places asymmetric side stones on even boards for 6 and 8.","family":"w2-go-territory-scoring-handicap-points-even-board-limit","id":"FA-82961","implementations":{"attempt":{"sha256":"a05471d91e8f1409a2afbecef284b3730cf28dc70a16fb553a1347fde6605ae7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    size, count = x\n    if count < 2 or count > 9:\n        return []\n    if size % 2 == 0 and count in (5, 7, 9):\n        return []\n    e = 2 if size < 13 else 3\n    f = size - 1 - e\n    mid = size // 2\n    pts = [[e, f], [f, e], [f, f], [e, e]]\n    if count >= 4:\n        pts = pts[:4]\n    else:\n        pts = pts[:count]\n    if count in (6, 7, 8, 9):\n        pts += [[mid, e], [mid, f]]\n    if count in (8, 9):\n        pts += [[e, mid], [f, mid]]\n    if count in (5, 7, 9):\n        pts.append([mid, mid])\n    return pts\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[[7, 7], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]]], [[7, 8], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]]], [[7, 9], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]]], [[7, 10], []], [[9, 0], []], [[9, 1], []], [[10, 5], []], [[10, 6], []]], [[[9, 3], [[2, 6], [6, 2], [6, 6]]], [[9, 4], [[2, 6], [6, 2], [6, 6], [2, 2]]], [[9, 5], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 4]]], [[9, 6], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6]]], [[9, 7], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6], [4, 4]]], [[9, 8], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6], [2, 4], [6, 4]]], [[10, 8], []], [[14, 8], []]], [[[9, 10], []], [[10, 0], []], [[10, 1], []], [[10, 2], [[2, 7], [7, 2]]], [[10, 3], [[2, 7], [7, 2], [7, 7]]], [[10, 4], [[2, 7], [7, 2], [7, 7], [2, 2]]], [[12, 6], []], [[14, 6], []]], [[[10, 6], []], [[10, 7], []], [[10, 8], []], [[10, 9], []], [[10, 10], []], [[11, 0], []], [[12, 8], []], [[12, 9], []]], [[[11, 2], [[2, 8], [8, 2]]], [[11, 3], [[2, 8], [8, 2], [8, 8]]], [[11, 4], [[2, 8], [8, 2], [8, 8], [2, 2]]], [[11, 5], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 5]]], [[11, 6], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 2], [5, 8]]], [[11, 7], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 2], [5, 8], [5, 5]]], [[12, 6], []], [[14, 7], []]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"handicap placement 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":"5a9e2b2f0c38e931d6e3eca734ba883ff5ec173163806bc767903de67efd931f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    size, count = x\n    if count < 2 or count > 9:\n        return []\n    e = 2 if size < 13 else 3\n    f = size - 1 - e\n    mid = size // 2\n    pts = [[e, f], [f, e], [f, f], [e, e]]\n    if count >= 4:\n        pts = pts[:4]\n    else:\n        pts = pts[:count]\n    if count in (6, 7, 8, 9):\n        pts += [[mid, e], [mid, f]]\n    if count in (8, 9):\n        pts += [[e, mid], [f, mid]]\n    if count in (5, 7, 9):\n        pts.append([mid, mid])\n    return pts\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[[7, 7], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]]], [[7, 8], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]]], [[7, 9], [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]]], [[7, 10], []], [[9, 0], []], [[9, 1], []], [[10, 5], []], [[10, 6], []]], [[[9, 3], [[2, 6], [6, 2], [6, 6]]], [[9, 4], [[2, 6], [6, 2], [6, 6], [2, 2]]], [[9, 5], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 4]]], [[9, 6], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6]]], [[9, 7], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6], [4, 4]]], [[9, 8], [[2, 6], [6, 2], [6, 6], [2, 2], [4, 2], [4, 6], [2, 4], [6, 4]]], [[10, 8], []], [[14, 8], []]], [[[9, 10], []], [[10, 0], []], [[10, 1], []], [[10, 2], [[2, 7], [7, 2]]], [[10, 3], [[2, 7], [7, 2], [7, 7]]], [[10, 4], [[2, 7], [7, 2], [7, 7], [2, 2]]], [[12, 6], []], [[14, 6], []]], [[[10, 6], []], [[10, 7], []], [[10, 8], []], [[10, 9], []], [[10, 10], []], [[11, 0], []], [[12, 8], []], [[12, 9], []]], [[[11, 2], [[2, 8], [8, 2]]], [[11, 3], [[2, 8], [8, 2], [8, 8]]], [[11, 4], [[2, 8], [8, 2], [8, 8], [2, 2]]], [[11, 5], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 5]]], [[11, 6], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 2], [5, 8]]], [[11, 7], [[2, 8], [8, 2], [8, 8], [2, 2], [5, 2], [5, 8], [5, 5]]], [[12, 6], []], [[14, 7], []]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"handicap placement 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-handicap-points-even-board-limit","generated_at":"2026-09-29T14:50:17.049674+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 even-board guard is missing, so mid is not a true centre line.","sha256":"a4cf3db029170b5eb7d33d3950a73d77baf2d62d81400772e18935735bbff4cc","title":"Even-sized boards receive side and centre handicap 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":41.227,"exit_code":1,"observations":[{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[3,3]],"check":"handicap placement case 0","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[3,3]],"passed":true},{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3]],"check":"handicap placement case 1","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3]],"passed":true},{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3],[3,3]],"check":"handicap placement case 2","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3],[3,3]],"passed":true},{"actual":[],"check":"handicap placement case 3","expected":[],"passed":true},{"actual":[],"check":"handicap placement case 4","expected":[],"passed":true},{"actual":[],"check":"handicap placement case 5","expected":[],"passed":true},{"actual":[],"check":"handicap placement case 6","expected":[],"passed":true},{"actual":[[2,7],[7,2],[7,7],[2,2],[5,2],[5,7]],"check":"handicap placement case 7","expected":[],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"handicap placement case 0\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]], \"passed\": true}, {\"check\": \"handicap placement case 1\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]], \"passed\": true}, {\"check\": \"handicap placement case 2\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]], \"passed\": true}, {\"check\": \"handicap placement case 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 6\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 7\", \"actual\": [[2, 7], [7, 2], [7, 7], [2, 2], [5, 2], [5, 7]], \"expected\": [], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.98,"exit_code":1,"observations":[{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[3,3]],"check":"handicap placement case 0","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[3,3]],"passed":true},{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3]],"check":"handicap placement case 1","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3]],"passed":true},{"actual":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3],[3,3]],"check":"handicap placement case 2","expected":[[2,4],[4,2],[4,4],[2,2],[3,2],[3,4],[2,3],[4,3],[3,3]],"passed":true},{"actual":[],"check":"handicap placement case 3","expected":[],"passed":true},{"actual":[],"check":"handicap placement case 4","expected":[],"passed":true},{"actual":[],"check":"handicap placement case 5","expected":[],"passed":true},{"actual":[[2,7],[7,2],[7,7],[2,2],[5,5]],"check":"handicap placement case 6","expected":[],"passed":false},{"actual":[[2,7],[7,2],[7,7],[2,2],[5,2],[5,7]],"check":"handicap placement case 7","expected":[],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"handicap placement case 0\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [3, 3]], \"passed\": true}, {\"check\": \"handicap placement case 1\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3]], \"passed\": true}, {\"check\": \"handicap placement case 2\", \"actual\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]], \"expected\": [[2, 4], [4, 2], [4, 4], [2, 2], [3, 2], [3, 4], [2, 3], [4, 3], [3, 3]], \"passed\": true}, {\"check\": \"handicap placement case 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"handicap placement case 6\", \"actual\": [[2, 7], [7, 2], [7, 7], [2, 2], [5, 5]], \"expected\": [], \"passed\": false}, {\"check\": \"handicap placement case 7\", \"actual\": [[2, 7], [7, 2], [7, 7], [2, 2], [5, 2], [5, 7]], \"expected\": [], \"passed\": false}], \"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."}}