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FA-82246 / Poker hand evaluation / Open access

Razz bring-in chosen as the lowest card · case 01

In razz the deuce brings in instead of the king.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The same minimum selection is used for every variant.

VERIFIED REPAIR

Razz selects the maximum (card, suit) key; stud selects the minimum.

Unsuccessful approach: Choosing by card value alone breaks ties by player name instead of suit.

Case contract

Input: {"variant": "stud", "stud8" or "razz", "up": {player: door card}}. In stud and stud8 the lowest door card brings in (ace high); ties are broken by suit with clubs lowest, then diamonds, hearts, spades. In razz the highest door card brings in (ace low), ties going to the highest suit. Return the bring-in player.

Why this case matters

The bring-in decides who is forced to act first on third street.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    R='23456789TJQKA'; S='cdhs'
    razz=x['variant']=='razz'
    def rv(c):
        if razz and c[0]=='A': return 1
        return R.index(c[0])+2
    def k(p):
        c=x['up'][p]
        return (rv(c), S.index(c[1]))
    players=sorted(x['up'])
    return min(players, key=k)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'error:' + type(exc).__name__
    check(label, actual, expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
lowest deucebbPassed
deuce suit tiebbPassed
ace is high in studbbPassed
razz ace lowacFailed
razz ace vs deuceacFailed
razz suit tiecbFailed
stud8 uses stud rulebbPassed
stud8 ace highbbPassed

SHA-256 / b05ce1029e1dfa222e4450f9cb25ab7a60da458f2b3e994308fb486541d8bd27

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    R='23456789TJQKA'; S='cdhs'
    razz=x['variant']=='razz'
    def rv(c):
        if razz and c[0]=='A': return 1
        return R.index(c[0])+2
    def k(p):
        c=x['up'][p]
        return (rv(c), S.index(c[1]))
    players=sorted(x['up'])
    return (max if razz else min)(players, key=lambda p: k(p)[0])
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'error:' + type(exc).__name__
    check(label, actual, expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
lowest deucebbPassed
deuce suit tieabFailed
ace is high in studbbPassed
razz ace lowccPassed
razz ace vs deuceccPassed
razz suit tieabFailed
stud8 uses stud rulebbPassed
stud8 ace highbbPassed

SHA-256 / 13bf896bb72dc998945a67a754a071efb914d8333dec3b672b31c8d2e448003f

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    R='23456789TJQKA'; S='cdhs'
    razz=x['variant']=='razz'
    def rv(c):
        if razz and c[0]=='A': return 1
        return R.index(c[0])+2
    def k(p):
        c=x['up'][p]
        return (rv(c), S.index(c[1]))
    players=sorted(x['up'])
    return max(players, key=k) if razz else min(players, key=k)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('spade vs heart tie stud', {'up': {'a': '4s', 'b': '4h', 'c': 'Js'}, 'variant': 'stud'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('lowest deuce', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('diamond vs club tie stud', {'up': {'a': '5d', 'b': '5c'}, 'variant': 'stud'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')],
 [('deuce suit tie', {'up': {'a': '2h', 'b': '2c', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('ace is high in stud', {'up': {'a': 'Ah', 'b': '3d', 'c': '9s'}, 'variant': 'stud'}, 'b'),
  ('razz ace low', {'up': {'a': 'Ah', 'b': '3d', 'c': 'Ks'}, 'variant': 'razz'}, 'c'),
  ('razz ace vs deuce', {'up': {'a': 'Ah', 'b': '2d', 'c': '5s'}, 'variant': 'razz'}, 'c'),
  ('razz suit tie', {'up': {'a': 'Kc', 'b': 'Ks', 'c': '5s'}, 'variant': 'razz'}, 'b'),
  ('stud8 uses stud rule', {'up': {'a': 'Kh', 'b': '2d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('stud8 ace high', {'up': {'a': 'Ad', 'b': '4d', 'c': '9s'}, 'variant': 'stud8'}, 'b'),
  ('razz heart vs diamond', {'up': {'a': 'Qd', 'b': 'Qh', 'c': '2s'}, 'variant': 'razz'}, 'b')]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'error:' + type(exc).__name__
    check(label, actual, expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
lowest deucebbPassed
deuce suit tiebbPassed
ace is high in studbbPassed
razz ace lowccPassed
razz ace vs deuceccPassed
razz suit tiebbPassed
stud8 uses stud rulebbPassed
stud8 ace highbbPassed

SHA-256 / b2d8abda641fa72d1c46ce0ecb7585567cbcc2e669ebec26ef1f00a8289a3f14

Verification & scope

A deterministic toy model with an explicitly stated contract; card strings are rank+suit (for example "As", "Td"); no claim of conformance to any casino or tournament rulebook. 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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:50:10.197816+00:00.

Case digest / d7b2d8694e32dc405fba9d51233482a907ea8f43a0dfca1620adba0aa7bab116