{"abstract":"A real move at column 20 row 20 on a 21x21 board is dropped as a pass.","category":"Go territory scoring","checks":8,"contract":"Input [size, text]. \"\" is a pass; \"tt\" is also a pass on boards up to 19x19. Otherwise exactly two lower-case letters: first = column, second = row, both from the top-left. Return [row, col], \"pass\" or \"invalid\".","evaluation_group":"w2-go-territory-scoring-sgf-point","failed_approach":"Using size < 19 stops recognising tt as pass on the standard 19x19 board.","family":"w2-go-territory-scoring-sgf-point-tt-pass-on-large-boards","id":"FA-82991","implementations":{"attempt":{"sha256":"1e1d8ec973cc1fd52d8f8faba1428a2b9590e2087c272ea5cab2959e811c4d31","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    size, text = x\n    if text == '':\n        return 'pass'\n    if text == 'tt' and size < 19:\n        return 'pass'\n    if len(text) != 2:\n        return 'invalid'\n    col = ord(text[0]) - ord('a')\n    row = ord(text[1]) - ord('a')\n    if not (0 <= col < size and 0 <= row < size):\n        return 'invalid'\n    return [row, col]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[[9, 'jj'], 'invalid'], [[9, 'Aa'], 'invalid'], [[9, 'aA'], 'invalid'], [[9, 'u'], 'invalid'], [[9, 'abc'], 'invalid'], [[9, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[9, 'ta'], 'invalid'], [[9, 'at'], 'invalid'], [[9, 'pd'], 'invalid'], [[9, 'dp'], 'invalid'], [[9, 'ia'], [0, 8]], [[9, 'ja'], 'invalid'], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'dd'], [3, 3]], [[13, 'aa'], [0, 0]], [[13, 'ss'], 'invalid'], [[13, 'tt'], 'pass'], [[13, ''], 'pass'], [[13, 'ab'], [1, 0]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[13, 'jj'], [9, 9]], [[13, 'Aa'], 'invalid'], [[13, 'aA'], 'invalid'], [[13, 'u'], 'invalid'], [[13, 'abc'], 'invalid'], [[13, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'ta'], 'invalid'], [[13, 'at'], 'invalid'], [[13, 'pd'], 'invalid'], [[13, 'dp'], 'invalid'], [[13, 'ma'], [0, 12]], [[13, 'na'], 'invalid'], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"sgf point 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":"642aea975275a16150459b29872dac5999430b23eaaab9f4c26b7d7d196f6963","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    size, text = x\n    if text == '':\n        return 'pass'\n    if text == 'tt':\n        return 'pass'\n    if len(text) != 2:\n        return 'invalid'\n    col = ord(text[0]) - ord('a')\n    row = ord(text[1]) - ord('a')\n    if not (0 <= col < size and 0 <= row < size):\n        return 'invalid'\n    return [row, col]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[[9, 'jj'], 'invalid'], [[9, 'Aa'], 'invalid'], [[9, 'aA'], 'invalid'], [[9, 'u'], 'invalid'], [[9, 'abc'], 'invalid'], [[9, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[9, 'ta'], 'invalid'], [[9, 'at'], 'invalid'], [[9, 'pd'], 'invalid'], [[9, 'dp'], 'invalid'], [[9, 'ia'], [0, 8]], [[9, 'ja'], 'invalid'], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'dd'], [3, 3]], [[13, 'aa'], [0, 0]], [[13, 'ss'], 'invalid'], [[13, 'tt'], 'pass'], [[13, ''], 'pass'], [[13, 'ab'], [1, 0]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[13, 'jj'], [9, 9]], [[13, 'Aa'], 'invalid'], [[13, 'aA'], 'invalid'], [[13, 'u'], 'invalid'], [[13, 'abc'], 'invalid'], [[13, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'ta'], 'invalid'], [[13, 'at'], 'invalid'], [[13, 'pd'], 'invalid'], [[13, 'dp'], 'invalid'], [[13, 'ma'], [0, 12]], [[13, 'na'], 'invalid'], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"sgf point 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"},"fixed":{"sha256":"a7a2bb831c2fdb4a302bd3fd256ddb142aa3cbe7d5d2d868d5ebae1f82655f2e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    size, text = x\n    if text == '':\n        return 'pass'\n    if text == 'tt' and size <= 19:\n        return 'pass'\n    if len(text) != 2:\n        return 'invalid'\n    col = ord(text[0]) - ord('a')\n    row = ord(text[1]) - ord('a')\n    if not (0 <= col < size and 0 <= row < size):\n        return 'invalid'\n    return [row, col]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[[[9, 'jj'], 'invalid'], [[9, 'Aa'], 'invalid'], [[9, 'aA'], 'invalid'], [[9, 'u'], 'invalid'], [[9, 'abc'], 'invalid'], [[9, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[9, 'ta'], 'invalid'], [[9, 'at'], 'invalid'], [[9, 'pd'], 'invalid'], [[9, 'dp'], 'invalid'], [[9, 'ia'], [0, 8]], [[9, 'ja'], 'invalid'], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'dd'], [3, 3]], [[13, 'aa'], [0, 0]], [[13, 'ss'], 'invalid'], [[13, 'tt'], 'pass'], [[13, ''], 'pass'], [[13, 'ab'], [1, 0]], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]], [[[13, 'jj'], [9, 9]], [[13, 'Aa'], 'invalid'], [[13, 'aA'], 'invalid'], [[13, 'u'], 'invalid'], [[13, 'abc'], 'invalid'], [[13, 'ia'], [0, 8]], [[19, 'tt'], 'pass'], [[25, 'tt'], [19, 19]]], [[[13, 'ta'], 'invalid'], [[13, 'at'], 'invalid'], [[13, 'pd'], 'invalid'], [[13, 'dp'], 'invalid'], [[13, 'ma'], [0, 12]], [[13, 'na'], 'invalid'], [[19, 'tt'], 'pass'], [[21, 'tt'], [19, 19]]]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check(\"sgf point 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-sgf-point-tt-pass-on-large-boards","generated_at":"2026-09-29T14:50:17.262414+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.","repair":"Accept tt as pass only when size <= 19.","root_cause":"The legacy tt pass is recognised without the board-size guard.","sha256":"133917fde0f5ac7227817327e7b5545d80832456418360060e43e6a34391e707","title":"tt is treated as a pass on boards larger than 19x19 · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.408,"exit_code":1,"observations":[{"actual":"invalid","check":"sgf point case 0","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 1","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 2","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 3","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 4","expected":"invalid","passed":true},{"actual":[0,8],"check":"sgf point case 5","expected":[0,8],"passed":true},{"actual":"invalid","check":"sgf point case 6","expected":"pass","passed":false},{"actual":[19,19],"check":"sgf point case 7","expected":[19,19],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"sgf point case 0\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 1\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 2\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 3\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 4\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 5\", \"actual\": [0, 8], \"expected\": [0, 8], \"passed\": true}, {\"check\": \"sgf point case 6\", \"actual\": \"invalid\", \"expected\": \"pass\", \"passed\": false}, {\"check\": \"sgf point case 7\", \"actual\": [19, 19], \"expected\": [19, 19], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.727,"exit_code":1,"observations":[{"actual":"invalid","check":"sgf point case 0","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 1","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 2","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 3","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 4","expected":"invalid","passed":true},{"actual":[0,8],"check":"sgf point case 5","expected":[0,8],"passed":true},{"actual":"pass","check":"sgf point case 6","expected":"pass","passed":true},{"actual":"pass","check":"sgf point case 7","expected":[19,19],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"sgf point case 0\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 1\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 2\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 3\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 4\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 5\", \"actual\": [0, 8], \"expected\": [0, 8], \"passed\": true}, {\"check\": \"sgf point case 6\", \"actual\": \"pass\", \"expected\": \"pass\", \"passed\": true}, {\"check\": \"sgf point case 7\", \"actual\": \"pass\", \"expected\": [19, 19], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.902,"exit_code":0,"observations":[{"actual":"invalid","check":"sgf point case 0","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 1","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 2","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 3","expected":"invalid","passed":true},{"actual":"invalid","check":"sgf point case 4","expected":"invalid","passed":true},{"actual":[0,8],"check":"sgf point case 5","expected":[0,8],"passed":true},{"actual":"pass","check":"sgf point case 6","expected":"pass","passed":true},{"actual":[19,19],"check":"sgf point case 7","expected":[19,19],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"sgf point case 0\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 1\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 2\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 3\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 4\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"sgf point case 5\", \"actual\": [0, 8], \"expected\": [0, 8], \"passed\": true}, {\"check\": \"sgf point case 6\", \"actual\": \"pass\", \"expected\": \"pass\", \"passed\": true}, {\"check\": \"sgf point case 7\", \"actual\": [19, 19], \"expected\": [19, 19], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}