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FA-83921 / Sports scoring and tiebreakers / Open access

Next set opened by the wrong server · case 01

After a set the team that won the last rally keeps serving instead of the alternating first server.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The server is not reassigned at the start of each set.

VERIFIED REPAIR

Alternate the first server by set number.

Unsuccessful approach: Giving the serve to the set winner still ignores the alternation rule.

Case contract

Best-of-five volleyball with rally scoring. rallies is a string of rally winners (A/B). Sets 1-4 are played to 25 and set 5 to 15, always win by two with no cap. The rally winner serves next; when the receiving team wins a rally (side-out) that team rotates once (rotation counter modulo 6). At the start of each set both rotation counters reset to 0 and the first server is first_serve in odd-numbered sets and the other team in even-numbered sets. Return [completed and current set scores as [a, b], match winner or None, rotation counters].

Why this case matters

Scoresheet apps track rotations to flag out-of-rotation faults and must reset them each set.

1 / The failure

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

N = 1
observations = []
def solve(rallies, first_serve):
    won = {'A': 0, 'B': 0}
    sets = []
    a = b = 0
    set_index = 0
    server = first_serve
    rot = {'A': 0, 'B': 0}
    for r in rallies:
        if r == 'A':
            a += 1
        else:
            b += 1
        if r != server:
            rot[r] = (rot[r] + 1) % 6
            server = r
        target = 15 if set_index == 4 else 25
        if max(a, b) >= target and abs(a - b) >= 2:
            w = 'A' if a > b else 'B'
            won[w] += 1
            sets.append([a, b])
            if won[w] == 3:
                return [sets, w, rot]
            a = b = 0
            set_index += 1
            rot = {'A': 0, 'B': 0}
    return [sets + ([[a, b]] if a or b else []), None, rot]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
def run(args):
    try:
        return solve(*args)
    except Exception as exc:
        return 'raised ' + type(exc).__name__
cases = [[('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABAAABABABAAABABABABAAABBBBABAABBBABAABBBAABBAAAABAABAABBA', 'A'),
   [[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]),
  ('variant scenario 1',
   ('BABBBAABBABABBBABAABAAAAABAABBABABABAABBABBABBAABBAB', 'A'),
   [[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('ABAABAAAAABAABBBBAABBAABBAABABAAAAAABAABBAA', 'B'),
   [[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('ABAABAAAAAAABABABAABBBAABBAAABBABAAAAABBAAAAAABABABABABBBBAAAABAABBBAAABAAAAAABABAAAA', 'B'),
   [[[25, 13], [25, 15], [5, 2]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAAAABABBAABBABBAAAAABBBBBAABA', 'A'),
   [[[17, 14]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('AAABBAAAABAAAAABBAAAABBBAAAABBAAABBAAAAAABBAABAAAAABBAAABBABBABABABBAAABAAAABAABAABBBBABBAABAAAAABBA',
    'A'),
   [[[25, 12], [25, 14], [13, 11]], None, {'A': 0, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAAAAAAAABBAABAAAAABBAABAAAABBAABBAAAAAABAABABBBBABAAABBAABAAAAABAAABABBAAABABBAAAAAABABABAAAABBABAB',
    'B'),
   [[[25, 6], [25, 15], [19, 13]], None, {'A': 3, 'B': 3}]),
  ('variant scenario 1',
   ('ABAABAAAAABAABBABBBAAAAAAABAABBBAAABBABABBBAAABAAAAAABAABBABBAABBAABAAABAABABABAAAAABAAAABAAABABBBBAAABAA',
    'A'),
   [[[25, 15], [25, 16], [16, 8]], None, {'A': 5, 'B': 5}]),
  ('variant scenario 2',
   ('ABABABAAAABAAAAABAAABAABBAAAAABAAABBBBABBAABAAABAABBAAAAABAAABAA', 'A'),
   [[[25, 9], [18, 12]], None, {'A': 1, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABBAAAAAAAABABAAABABAAABABBAABAABBABBBBBABA', 'A'),
   [[[25, 12], [2, 6]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAABAAAAAAABAABBAAAABAAAAAABAAAAAAAAAAABAAABABAAABABABBAAABAAAAABAABBAAABABABBBBAAABAAAABBABAABBABABBBBABAAAAAABBAAAAAAABBABABBAB',
    'A'),
   [[[25, 7], [25, 8], [25, 21]], 'A', {'A': 0, 'B': 0}]),
  ('variant scenario 2',
   ('ABAAAAAAAABBBABAAAAAAABBBBBAAABAAAABBABABAABAABBABBAAAAAABAABAABAA', 'B'),
   [[[25, 13], [18, 10]], None, {'A': 2, 'B': 2}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAABAABABABAAABBABBAAAAAABAABAAAAABAAAABAAAABABBAABAABBABABAABAABBBABAABABBAABAAAAAAABAA',
    'B'),
   [[[25, 10], [25, 16], [11, 4]], None, {'A': 3, 'B': 2}]),
  ('variant scenario 1',
   ('ABAABAABAAAABAAABBBBAAAAABBABABABAAABBBAAAAABAABBABABABAAABAAAAAAAABAAAAAAAABAAAAAAAABBAAAABABABAABABAABAABAAABBBAAABAAAABAAAAAAABAAAABAABBBBAABBAABAABBAAAABBAABBAAA',
    'A'),
   [[[25, 16], [25, 8], [25, 10]], 'A', {'A': 3, 'B': 3}]),
  ('variant scenario 2',
   ('AAABBAABBBBBAAAAABBAAABBAABAAABAAABAABBAAABAABBBBBBBAABBAAAAABAAAABBAABBAABABBBAAAAAABAABAAAAABBBBBBABAABABAAAAABB',
    'A'),
   [[[25, 16], [25, 19], [16, 13]], None, {'A': 0, 'B': 1}])]]
for label, args, expected in cases[N - 1]:
    check(label, run(args), 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
control first rally held by server[[[1, 0]], None, {'A': 0, 'B': 0}][[[1, 0]], None, {'A': 0, 'B': 0}]Passed
boundary side-out rotates receiver[[[0, 1]], None, {'A': 0, 'B': 1}][[[0, 1]], None, {'A': 0, 'B': 1}]Passed
control clean set[[[25, 0]], None, {'A': 0, 'B': 0}][[[25, 0]], None, {'A': 0, 'B': 0}]Passed
boundary second set served by other team[[[25, 0], [1, 0]], None, {'A': 0, 'B': 0}][[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]Failed
boundary deuce in set[[[26, 24]], None, {'A': 0, 'B': 0}][[[26, 24]], None, {'A': 0, 'B': 0}]Passed
control straight-sets match[[[25, 0], [25, 0], [25, 0]], 'A', {'A': 0, 'B': 0}][[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]Failed
regression: set first server[[[25, 20], [9, 6]], None, {'A': 4, 'B': 4}][[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]Failed
variant scenario 1[[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}][[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]Passed
variant scenario 2[[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}][[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}]Passed

SHA-256 / cbb5411c7b867b9a6c0d4e61eddc8f6c356cff45b19ba00febae72f3a88e6847

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(rallies, first_serve):
    won = {'A': 0, 'B': 0}
    sets = []
    a = b = 0
    set_index = 0
    server = first_serve
    rot = {'A': 0, 'B': 0}
    for r in rallies:
        if r == 'A':
            a += 1
        else:
            b += 1
        if r != server:
            rot[r] = (rot[r] + 1) % 6
            server = r
        target = 15 if set_index == 4 else 25
        if max(a, b) >= target and abs(a - b) >= 2:
            w = 'A' if a > b else 'B'
            won[w] += 1
            sets.append([a, b])
            if won[w] == 3:
                return [sets, w, rot]
            a = b = 0
            set_index += 1
            rot = {'A': 0, 'B': 0}
            server = w
    return [sets + ([[a, b]] if a or b else []), None, rot]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
def run(args):
    try:
        return solve(*args)
    except Exception as exc:
        return 'raised ' + type(exc).__name__
cases = [[('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABAAABABABAAABABABABAAABBBBABAABBBABAABBBAABBAAAABAABAABBA', 'A'),
   [[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]),
  ('variant scenario 1',
   ('BABBBAABBABABBBABAABAAAAABAABBABABABAABBABBABBAABBAB', 'A'),
   [[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('ABAABAAAAABAABBBBAABBAABBAABABAAAAAABAABBAA', 'B'),
   [[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('ABAABAAAAAAABABABAABBBAABBAAABBABAAAAABBAAAAAABABABABABBBBAAAABAABBBAAABAAAAAABABAAAA', 'B'),
   [[[25, 13], [25, 15], [5, 2]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAAAABABBAABBABBAAAAABBBBBAABA', 'A'),
   [[[17, 14]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('AAABBAAAABAAAAABBAAAABBBAAAABBAAABBAAAAAABBAABAAAAABBAAABBABBABABABBAAABAAAABAABAABBBBABBAABAAAAABBA',
    'A'),
   [[[25, 12], [25, 14], [13, 11]], None, {'A': 0, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAAAAAAAABBAABAAAAABBAABAAAABBAABBAAAAAABAABABBBBABAAABBAABAAAAABAAABABBAAABABBAAAAAABABABAAAABBABAB',
    'B'),
   [[[25, 6], [25, 15], [19, 13]], None, {'A': 3, 'B': 3}]),
  ('variant scenario 1',
   ('ABAABAAAAABAABBABBBAAAAAAABAABBBAAABBABABBBAAABAAAAAABAABBABBAABBAABAAABAABABABAAAAABAAAABAAABABBBBAAABAA',
    'A'),
   [[[25, 15], [25, 16], [16, 8]], None, {'A': 5, 'B': 5}]),
  ('variant scenario 2',
   ('ABABABAAAABAAAAABAAABAABBAAAAABAAABBBBABBAABAAABAABBAAAAABAAABAA', 'A'),
   [[[25, 9], [18, 12]], None, {'A': 1, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABBAAAAAAAABABAAABABAAABABBAABAABBABBBBBABA', 'A'),
   [[[25, 12], [2, 6]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAABAAAAAAABAABBAAAABAAAAAABAAAAAAAAAAABAAABABAAABABABBAAABAAAAABAABBAAABABABBBBAAABAAAABBABAABBABABBBBABAAAAAABBAAAAAAABBABABBAB',
    'A'),
   [[[25, 7], [25, 8], [25, 21]], 'A', {'A': 0, 'B': 0}]),
  ('variant scenario 2',
   ('ABAAAAAAAABBBABAAAAAAABBBBBAAABAAAABBABABAABAABBABBAAAAAABAABAABAA', 'B'),
   [[[25, 13], [18, 10]], None, {'A': 2, 'B': 2}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAABAABABABAAABBABBAAAAAABAABAAAAABAAAABAAAABABBAABAABBABABAABAABBBABAABABBAABAAAAAAABAA',
    'B'),
   [[[25, 10], [25, 16], [11, 4]], None, {'A': 3, 'B': 2}]),
  ('variant scenario 1',
   ('ABAABAABAAAABAAABBBBAAAAABBABABABAAABBBAAAAABAABBABABABAAABAAAAAAAABAAAAAAAABAAAAAAAABBAAAABABABAABABAABAABAAABBBAAABAAAABAAAAAAABAAAABAABBBBAABBAABAABBAAAABBAABBAAA',
    'A'),
   [[[25, 16], [25, 8], [25, 10]], 'A', {'A': 3, 'B': 3}]),
  ('variant scenario 2',
   ('AAABBAABBBBBAAAAABBAAABBAABAAABAAABAABBAAABAABBBBBBBAABBAAAAABAAAABBAABBAABABBBAAAAAABAABAAAAABBBBBBABAABABAAAAABB',
    'A'),
   [[[25, 16], [25, 19], [16, 13]], None, {'A': 0, 'B': 1}])]]
for label, args, expected in cases[N - 1]:
    check(label, run(args), 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
control first rally held by server[[[1, 0]], None, {'A': 0, 'B': 0}][[[1, 0]], None, {'A': 0, 'B': 0}]Passed
boundary side-out rotates receiver[[[0, 1]], None, {'A': 0, 'B': 1}][[[0, 1]], None, {'A': 0, 'B': 1}]Passed
control clean set[[[25, 0]], None, {'A': 0, 'B': 0}][[[25, 0]], None, {'A': 0, 'B': 0}]Passed
boundary second set served by other team[[[25, 0], [1, 0]], None, {'A': 0, 'B': 0}][[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]Failed
boundary deuce in set[[[26, 24]], None, {'A': 0, 'B': 0}][[[26, 24]], None, {'A': 0, 'B': 0}]Passed
control straight-sets match[[[25, 0], [25, 0], [25, 0]], 'A', {'A': 0, 'B': 0}][[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]Failed
regression: set first server[[[25, 20], [9, 6]], None, {'A': 4, 'B': 4}][[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]Failed
variant scenario 1[[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}][[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]Passed
variant scenario 2[[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}][[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}]Passed

SHA-256 / 3f2eb078edc64bd4e271c1a046d5c10b1f517a5ca71426431755fa22a2a1f9bd

3 / The verified repair

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

N = 1
observations = []
def solve(rallies, first_serve):
    won = {'A': 0, 'B': 0}
    sets = []
    a = b = 0
    set_index = 0
    server = first_serve
    rot = {'A': 0, 'B': 0}
    for r in rallies:
        if r == 'A':
            a += 1
        else:
            b += 1
        if r != server:
            rot[r] = (rot[r] + 1) % 6
            server = r
        target = 15 if set_index == 4 else 25
        if max(a, b) >= target and abs(a - b) >= 2:
            w = 'A' if a > b else 'B'
            won[w] += 1
            sets.append([a, b])
            if won[w] == 3:
                return [sets, w, rot]
            a = b = 0
            set_index += 1
            rot = {'A': 0, 'B': 0}
            server = first_serve if set_index % 2 == 0 else ('B' if first_serve == 'A' else 'A')
    return [sets + ([[a, b]] if a or b else []), None, rot]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
def run(args):
    try:
        return solve(*args)
    except Exception as exc:
        return 'raised ' + type(exc).__name__
cases = [[('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABAAABABABAAABABABABAAABBBBABAABBBABAABBBAABBAAAABAABAABBA', 'A'),
   [[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]),
  ('variant scenario 1',
   ('BABBBAABBABABBBABAABAAAAABAABBABABABAABBABBABBAABBAB', 'A'),
   [[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('ABAABAAAAABAABBBBAABBAABBAABABAAAAAABAABBAA', 'B'),
   [[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('ABAABAAAAAAABABABAABBBAABBAAABBABAAAAABBAAAAAABABABABABBBBAAAABAABBBAAABAAAAAABABAAAA', 'B'),
   [[[25, 13], [25, 15], [5, 2]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAAAABABBAABBABBAAAAABBBBBAABA', 'A'),
   [[[17, 14]], None, {'A': 1, 'B': 1}]),
  ('variant scenario 2',
   ('AAABBAAAABAAAAABBAAAABBBAAAABBAAABBAAAAAABBAABAAAAABBAAABBABBABABABBAAABAAAABAABAABBBBABBAABAAAAABBA',
    'A'),
   [[[25, 12], [25, 14], [13, 11]], None, {'A': 0, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAAAAAAAABBAABAAAAABBAABAAAABBAABBAAAAAABAABABBBBABAAABBAABAAAAABAAABABBAAABABBAAAAAABABABAAAABBABAB',
    'B'),
   [[[25, 6], [25, 15], [19, 13]], None, {'A': 3, 'B': 3}]),
  ('variant scenario 1',
   ('ABAABAAAAABAABBABBBAAAAAAABAABBBAAABBABABBBAAABAAAAAABAABBABBAABBAABAAABAABABABAAAAABAAAABAAABABBBBAAABAA',
    'A'),
   [[[25, 15], [25, 16], [16, 8]], None, {'A': 5, 'B': 5}]),
  ('variant scenario 2',
   ('ABABABAAAABAAAAABAAABAABBAAAAABAAABBBBABBAABAAABAABBAAAAABAAABAA', 'A'),
   [[[25, 9], [18, 12]], None, {'A': 1, 'B': 0}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAABBAAAAAAAABABAAABABAAABABBAABAABBABBBBBABA', 'A'),
   [[[25, 12], [2, 6]], None, {'A': 2, 'B': 1}]),
  ('variant scenario 1',
   ('BAAABAAAAAAABAABBAAAABAAAAAABAAAAAAAAAAABAAABABAAABABABBAAABAAAAABAABBAAABABABBBBAAABAAAABBABAABBABABBBBABAAAAAABBAAAAAAABBABABBAB',
    'A'),
   [[[25, 7], [25, 8], [25, 21]], 'A', {'A': 0, 'B': 0}]),
  ('variant scenario 2',
   ('ABAAAAAAAABBBABAAAAAAABBBBBAAABAAAABBABABAABAABBABBAAAAAABAABAABAA', 'B'),
   [[[25, 13], [18, 10]], None, {'A': 2, 'B': 2}])],
 [('control first rally held by server', ('A', 'A'), [[[1, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary side-out rotates receiver', ('B', 'A'), [[[0, 1]], None, {'A': 0, 'B': 1}]),
  ('control clean set', ('AAAAAAAAAAAAAAAAAAAAAAAAA', 'A'), [[[25, 0]], None, {'A': 0, 'B': 0}]),
  ('boundary second set served by other team',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAA', 'A'),
   [[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]),
  ('boundary deuce in set',
   ('ABABABABABABABABABABABABABABABABABABABABABABABABAA', 'A'),
   [[[26, 24]], None, {'A': 0, 'B': 0}]),
  ('control straight-sets match',
   ('AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA', 'B'),
   [[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]),
  ('regression: set first server',
   ('AAAAAABAABABABAAABBABBAAAAAABAABAAAAABAAAABAAAABABBAABAABBABABAABAABBBABAABABBAABAAAAAAABAA',
    'B'),
   [[[25, 10], [25, 16], [11, 4]], None, {'A': 3, 'B': 2}]),
  ('variant scenario 1',
   ('ABAABAABAAAABAAABBBBAAAAABBABABABAAABBBAAAAABAABBABABABAAABAAAAAAAABAAAAAAAABAAAAAAAABBAAAABABABAABABAABAABAAABBBAAABAAAABAAAAAAABAAAABAABBBBAABBAABAABBAAAABBAABBAAA',
    'A'),
   [[[25, 16], [25, 8], [25, 10]], 'A', {'A': 3, 'B': 3}]),
  ('variant scenario 2',
   ('AAABBAABBBBBAAAAABBAAABBAABAAABAAABAABBAAABAABBBBBBBAABBAAAAABAAAABBAABBAABABBBAAAAAABAABAAAAABBBBBBABAABABAAAAABB',
    'A'),
   [[[25, 16], [25, 19], [16, 13]], None, {'A': 0, 'B': 1}])]]
for label, args, expected in cases[N - 1]:
    check(label, run(args), 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
control first rally held by server[[[1, 0]], None, {'A': 0, 'B': 0}][[[1, 0]], None, {'A': 0, 'B': 0}]Passed
boundary side-out rotates receiver[[[0, 1]], None, {'A': 0, 'B': 1}][[[0, 1]], None, {'A': 0, 'B': 1}]Passed
control clean set[[[25, 0]], None, {'A': 0, 'B': 0}][[[25, 0]], None, {'A': 0, 'B': 0}]Passed
boundary second set served by other team[[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}][[[25, 0], [1, 0]], None, {'A': 1, 'B': 0}]Passed
boundary deuce in set[[[26, 24]], None, {'A': 0, 'B': 0}][[[26, 24]], None, {'A': 0, 'B': 0}]Passed
control straight-sets match[[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}][[[25, 0], [25, 0], [25, 0]], 'A', {'A': 1, 'B': 0}]Passed
regression: set first server[[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}][[[25, 20], [9, 6]], None, {'A': 4, 'B': 3}]Passed
variant scenario 1[[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}][[[24, 26], [1, 1]], None, {'A': 1, 'B': 1}]Passed
variant scenario 2[[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}][[[25, 14], [2, 2]], None, {'A': 1, 'B': 1}]Passed

SHA-256 / 1e17ec6f1418b445182521c43a40721e050d5d97a13fc2e523e9880893116978

Verification & scope

Stipulated, bounded toy contract stated in the contract field; not a claim of conformance with any governing body rulebook or operator house rules. 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 2026-09-29T14:50:25.949045+00:00.

Case digest / c5de58d9b3981d0903874b6f8ea6fb3cc830a3039bf0ef0cd64422ee7c3b3e01