{"abstract":"A 3.00 price is displayed as 3/1 instead of 2/1.","category":"Betting odds conversion","checks":10,"contract":"Display a decimal price (> 1, else \"invalid\") as the nearest traditional fraction from the ascending ladder ['1/10', '1/8', '1/5', '2/9', '1/4', '2/7', '1/3', '4/11', '2/5', '4/9', '1/2', '8/15', '4/7', '8/13', '4/6', '8/11', '4/5', '5/6', '10/11', 'evens', '11/10', '6/5', '5/4', '11/8', '6/4', '13/8', '7/4', '15/8', '2/1', '9/4', '5/2', '11/4', '3/1', '10/3', '7/2', '4/1', '9/2', '5/1', '11/2', '6/1', '13/2', '7/1', '15/2', '8/1', '17/2', '9/1', '10/1', '11/1', '12/1', '14/1', '16/1', '18/1', '20/1', '25/1', '33/1', '40/1', '50/1', '66/1', '100/1']. Distance is |fraction value - (d - 1)| with \"evens\" = 1; ties go to the earlier (shorter) ladder entry. Return the ladder string.","contract_signature":"decimal","evaluation_group":"w2-odds-conversion-traditional-fraction-display","failed_approach":"Using the reciprocal of the profit mixes odds-on and odds-against.","family":"w2-odds-conversion-traditional-fraction-display-profit-offset","id":"FA-84631","implementations":{"attempt":{"sha256":"ac288e3255a2fe92439fa6099f38032ecaaa0634a3431ed23992f5091b5e5d84","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(decimal):\n    LADDER = ['1/10', '1/8', '1/5', '2/9', '1/4', '2/7', '1/3', '4/11', '2/5', '4/9', '1/2', '8/15', '4/7', '8/13', '4/6', '8/11', '4/5', '5/6', '10/11', 'evens', '11/10', '6/5', '5/4', '11/8', '6/4', '13/8', '7/4', '15/8', '2/1', '9/4', '5/2', '11/4', '3/1', '10/3', '7/2', '4/1', '9/2', '5/1', '11/2', '6/1', '13/2', '7/1', '15/2', '8/1', '17/2', '9/1', '10/1', '11/1', '12/1', '14/1', '16/1', '18/1', '20/1', '25/1', '33/1', '40/1', '50/1', '66/1', '100/1']\n    def val(s):\n        return Fraction(1) if s == 'evens' else Fraction(s)\n    d = Fraction(decimal)\n    if d <= 1:\n        return 'invalid'\n    target = 1 / (d - 1)\n    best = None\n    for s in LADDER:\n        dist = abs(val(s) - target)\n        if best is None or dist < best[0]:\n            best = (dist, s)\n    return best[1]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ndef run(args):\n    try:\n        return solve(*args)\n    except Exception as exc:\n        return 'raised ' + type(exc).__name__\ncases = [[('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('71.7',), '66/1'),\n  ('regression: profit offset', ('19.1',), '18/1'),\n  ('variant scenario 1', ('1.95',), '10/11'),\n  ('variant scenario 2', ('85.5',), '100/1')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('85.8',), '100/1'),\n  ('regression: profit offset', ('1.95',), '10/11'),\n  ('variant scenario 1', ('2.125',), '11/10'),\n  ('variant scenario 2', ('6.42',), '11/2')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('1.201',), '1/5'),\n  ('variant scenario 1', ('3.875',), '11/4'),\n  ('variant scenario 2', ('5.53',), '9/2')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('1.95',), '10/11'),\n  ('variant scenario 1', ('3.875',), '11/4'),\n  ('variant scenario 2', ('11.07',), '10/1')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('3.452',), '5/2'),\n  ('variant scenario 1', ('1.95',), '10/11'),\n  ('variant scenario 2', ('6.93',), '6/1')]]\nfor label, args, expected in cases[N - 1]:\n    check(label, run(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":"d3ed27f88dee39a6930b121c59ce54e5771c32069aa37fd6945a35420256bae9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(decimal):\n    LADDER = ['1/10', '1/8', '1/5', '2/9', '1/4', '2/7', '1/3', '4/11', '2/5', '4/9', '1/2', '8/15', '4/7', '8/13', '4/6', '8/11', '4/5', '5/6', '10/11', 'evens', '11/10', '6/5', '5/4', '11/8', '6/4', '13/8', '7/4', '15/8', '2/1', '9/4', '5/2', '11/4', '3/1', '10/3', '7/2', '4/1', '9/2', '5/1', '11/2', '6/1', '13/2', '7/1', '15/2', '8/1', '17/2', '9/1', '10/1', '11/1', '12/1', '14/1', '16/1', '18/1', '20/1', '25/1', '33/1', '40/1', '50/1', '66/1', '100/1']\n    def val(s):\n        return Fraction(1) if s == 'evens' else Fraction(s)\n    d = Fraction(decimal)\n    if d <= 1:\n        return 'invalid'\n    target = d\n    best = None\n    for s in LADDER:\n        dist = abs(val(s) - target)\n        if best is None or dist < best[0]:\n            best = (dist, s)\n    return best[1]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ndef run(args):\n    try:\n        return solve(*args)\n    except Exception as exc:\n        return 'raised ' + type(exc).__name__\ncases = [[('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('71.7',), '66/1'),\n  ('regression: profit offset', ('19.1',), '18/1'),\n  ('variant scenario 1', ('1.95',), '10/11'),\n  ('variant scenario 2', ('85.5',), '100/1')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('85.8',), '100/1'),\n  ('regression: profit offset', ('1.95',), '10/11'),\n  ('variant scenario 1', ('2.125',), '11/10'),\n  ('variant scenario 2', ('6.42',), '11/2')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('1.201',), '1/5'),\n  ('variant scenario 1', ('3.875',), '11/4'),\n  ('variant scenario 2', ('5.53',), '9/2')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('1.95',), '10/11'),\n  ('variant scenario 1', ('3.875',), '11/4'),\n  ('variant scenario 2', ('11.07',), '10/1')],\n [('control exact fraction', ('3.50',), '5/2'),\n  ('control evens', ('2.00',), 'evens'),\n  ('boundary odds-on', ('1.67',), '4/6'),\n  ('boundary midpoint tie', ('3.875',), '11/4'),\n  ('control long shot', ('120.0',), '100/1'),\n  ('boundary no-profit price', ('1.00',), 'invalid'),\n  ('regression: profit offset', ('3.452',), '5/2'),\n  ('variant scenario 1', ('1.95',), '10/11'),\n  ('variant scenario 2', ('6.93',), '6/1')]]\nfor label, args, expected in cases[N - 1]:\n    check(label, run(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":"Stipulated, bounded toy contract stated in the contract field; not a claim of conformance with any operator, exchange or regulator rule set. 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-odds-conversion-traditional-fraction-display-profit-offset","generated_at":"2026-09-29T14:50:32.697755+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"UK-facing sites display decimal model prices as familiar traditional fractions.","root_cause":"The target is the decimal price itself instead of d - 1.","sha256":"a2409f0b3025a847198e043cfd195ed017ead7b4a478b5b3ae98d75d089501da","title":"Decimal price compared with fractions without removing the stake · 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":43.958,"exit_code":1,"observations":[{"actual":"2/5","check":"control exact fraction","expected":"5/2","passed":false},{"actual":"evens","check":"control evens","expected":"evens","passed":true},{"actual":"6/4","check":"boundary odds-on","expected":"4/6","passed":false},{"actual":"1/3","check":"boundary midpoint tie","expected":"11/4","passed":false},{"actual":"1/10","check":"control long shot","expected":"100/1","passed":false},{"actual":"invalid","check":"boundary no-profit price","expected":"invalid","passed":true},{"actual":"1/10","check":"regression: profit offset","expected":"66/1","passed":false},{"actual":"1/10","check":"regression: profit offset","expected":"18/1","passed":false},{"actual":"11/10","check":"variant scenario 1","expected":"10/11","passed":false},{"actual":"1/10","check":"variant scenario 2","expected":"100/1","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"control exact fraction\", \"actual\": \"2/5\", \"expected\": \"5/2\", \"passed\": false}, {\"check\": \"control evens\", \"actual\": \"evens\", \"expected\": \"evens\", \"passed\": true}, {\"check\": \"boundary odds-on\", \"actual\": \"6/4\", \"expected\": \"4/6\", \"passed\": false}, {\"check\": \"boundary midpoint tie\", \"actual\": \"1/3\", \"expected\": \"11/4\", \"passed\": false}, {\"check\": \"control long shot\", \"actual\": \"1/10\", \"expected\": \"100/1\", \"passed\": false}, {\"check\": \"boundary no-profit price\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"regression: profit offset\", \"actual\": \"1/10\", \"expected\": \"66/1\", \"passed\": false}, {\"check\": \"regression: profit offset\", \"actual\": \"1/10\", \"expected\": \"18/1\", \"passed\": false}, {\"check\": \"variant scenario 1\", \"actual\": \"11/10\", \"expected\": \"10/11\", \"passed\": false}, {\"check\": \"variant scenario 2\", \"actual\": \"1/10\", \"expected\": \"100/1\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":44.891,"exit_code":1,"observations":[{"actual":"7/2","check":"control exact fraction","expected":"5/2","passed":false},{"actual":"2/1","check":"control evens","expected":"evens","passed":false},{"actual":"13/8","check":"boundary odds-on","expected":"4/6","passed":false},{"actual":"4/1","check":"boundary midpoint tie","expected":"11/4","passed":false},{"actual":"100/1","check":"control long shot","expected":"100/1","passed":true},{"actual":"invalid","check":"boundary no-profit price","expected":"invalid","passed":true},{"actual":"66/1","check":"regression: profit offset","expected":"66/1","passed":true},{"actual":"20/1","check":"regression: profit offset","expected":"18/1","passed":false},{"actual":"2/1","check":"variant scenario 1","expected":"10/11","passed":false},{"actual":"100/1","check":"variant scenario 2","expected":"100/1","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"control exact fraction\", \"actual\": \"7/2\", \"expected\": \"5/2\", \"passed\": false}, {\"check\": \"control evens\", \"actual\": \"2/1\", \"expected\": \"evens\", \"passed\": false}, {\"check\": \"boundary odds-on\", \"actual\": \"13/8\", \"expected\": \"4/6\", \"passed\": false}, {\"check\": \"boundary midpoint tie\", \"actual\": \"4/1\", \"expected\": \"11/4\", \"passed\": false}, {\"check\": \"control long shot\", \"actual\": \"100/1\", \"expected\": \"100/1\", \"passed\": true}, {\"check\": \"boundary no-profit price\", \"actual\": \"invalid\", \"expected\": \"invalid\", \"passed\": true}, {\"check\": \"regression: profit offset\", \"actual\": \"66/1\", \"expected\": \"66/1\", \"passed\": true}, {\"check\": \"regression: profit offset\", \"actual\": \"20/1\", \"expected\": \"18/1\", \"passed\": false}, {\"check\": \"variant scenario 1\", \"actual\": \"2/1\", \"expected\": \"10/11\", \"passed\": false}, {\"check\": \"variant scenario 2\", \"actual\": \"100/1\", \"expected\": \"100/1\", \"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."}}