{ "evaluation_id": "EVAL-20260403-125023", "question_id": "CODE-016", "question_text": "Given these hex dumps of network packets and their known meanings, reverse-engineer the binary protocol format and write a parser.\n\nPacket 1 (Login): 4d 56 01 00 0c 68 65 6c 6c 6f 5f 77 6f 72 6c 64 00 00 00 05 61 64 6d 69 6e\nKnown: username=\"hello_world\", password=\"admin\"\n\nPacket 2 (Login): 4d 56 01 00 08 74 65 73 74 75 73 65 72 00 00 00 04 70 61 73 73\nKnown: username=\"testuser\", password=\"pass\"\n\nPacket 3 (Message): 4d 56 02 00 05 68 65 6c 6c 6f 00 00 00 01\nKnown: message=\"hello\", room_id=1\n\nWrite the protocol specification and a Python parser/serializer.", "category": "code", "timestamp": "2026-04-03T12:50:23.250Z", "display_date": "Apr 03, 2026", "winner": { "name": "GPT-OSS-120B", "provider": "OpenAI", "score": 9.38 }, "avg_score": 6.1866665, "matrix_size": 76, "models_used": [ { "id": "claude_opus_46", "name": "Claude Opus 4.6", "provider": "openrouter" }, { "id": "gemini_31_pro", "name": "Gemini 3.1 Pro", "provider": "openrouter" }, { "id": "claude_sonnet_46", "name": "Claude Sonnet 4.6", "provider": "openrouter" }, { "id": "grok_420", "name": "Grok 4.20", "provider": "openrouter" }, { "id": "deepseek_v4", "name": "DeepSeek V4", "provider": "openrouter" }, { "id": "gpt_oss_120b", "name": "GPT-OSS-120B", "provider": "OpenAI" }, { "id": "gemini_3_flash", "name": "Gemini 3 Flash Preview", "provider": "Google" }, { "id": "mimo_v2_flash", "name": "MiMo-V2-Flash", "provider": "Xiaomi" }, { "id": "gpt_5_4", "name": "GPT-5.4", "provider": "openrouter" } ], "rankings": { "gpt_oss_120b": { "display_name": "GPT-OSS-120B", "provider": "OpenAI", "average_score": 9.38, "score_count": 9, "min_score": 7.5, "max_score": 10, "rank": 1 }, "gpt_5_4": { "display_name": "GPT-5.4", "provider": "openrouter", "average_score": 9.08, "score_count": 9, "min_score": 8.8, "max_score": 10, "rank": 2 }, "gemini_3_flash": { "display_name": "Gemini 3 Flash Preview", "provider": "Google", "average_score": 7.37, "score_count": 9, "min_score": 4.2, "max_score": 9, "rank": 3 }, "grok_420": { "display_name": "Grok 4.20", "provider": "openrouter", "average_score": 7.29, "score_count": 7, "min_score": 2.95, "max_score": 10, "rank": 4 }, "mimo_v2_flash": { "display_name": "MiMo-V2-Flash", "provider": "Xiaomi", "average_score": 6.81, "score_count": 9, "min_score": 4.2, "max_score": 10, "rank": 5 }, "deepseek_v4": { "display_name": "DeepSeek V4", "provider": "openrouter", "average_score": 5.46, "score_count": 8, "min_score": 3.75, "max_score": 8.6, "rank": 6 }, "claude_sonnet_46": { "display_name": "Claude Sonnet 4.6", "provider": "openrouter", "average_score": 4.62, "score_count": 9, "min_score": 2.25, "max_score": 6.85, "rank": 7 }, "claude_opus_46": { "display_name": "Claude Opus 4.6", "provider": "openrouter", "average_score": 4.32, "score_count": 7, "min_score": 1.85, "max_score": 6.75, "rank": 8 }, "gemini_31_pro": { "display_name": "Gemini 3.1 Pro", "provider": "openrouter", "average_score": 1.35, "score_count": 9, "min_score": 0.45, "max_score": 2.85, "rank": 9 } }, "judgments": [ { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 1.85, "brief_justification": "The response is incomplete and never produces a final protocol spec or Python parser/serializer. It shows some exploratory analysis, but gets stuck on an inconsistency in Packet 1 and does not resolve it, so it is of little practical use." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 0.45, "brief_justification": "The response is fragmentary and unfinished, with no actual protocol specification or parser/serializer. It only begins to inspect bytes and expresses uncertainty, providing almost no actionable or complete content." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 2.25, "brief_justification": "The response is incomplete and cuts off before providing a final protocol spec or any Python parser/serializer. It shows some reasoning, but settles on a dubious interpretation and does not fully analyze Packet 3." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 2.95, "brief_justification": "Well-structured and clear, but the inferred format is largely incorrect: it misreads the header fields and payload lengths, so the parser would not parse the provided packets correctly or round-trip them exactly. Some practical code is provided, but it is not useful for the actual wire format." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 3.75, "brief_justification": "Well-structured, but it misidentifies key fields: the byte after type is a length prefix, not flags; strings are length-prefixed rather than null-terminated; password is not fixed 4 bytes; and room_id endianness/placement are inferred incorrectly. Parser/serializer therefore do not match the provided packets." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9, "brief_justification": "Accurately infers the format from the samples and provides a clear, working parser/serializer with examples. Minor deduction because it assumes reserved byte semantics and lacks robust bounds/malformed-input validation despite mentioning errors." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 4.2, "brief_justification": "Well-structured and clear, but it misreads the packet format: the dumps show 1-byte reserved + 1-byte length for the first string field, not a 4-byte big-endian length, so the proposed spec/parser do not actually match the provided packets and serialization would be incompatible." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 4.2, "brief_justification": "Well-structured, but the reverse engineering is largely incorrect: it misreads the field lengths as 4-byte little-endian for all fields, while the dumps indicate 1-byte length-prefixed strings and a 4-byte big-endian integer room_id. It also wrongly claims room_id is ASCII. The provided parser/serializer would not correctly parse or reproduce the sample packets." }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 8.95, "brief_justification": "The reverse-engineering is thorough and mostly correct. The protocol specification is clearly laid out with tables and offset diagrams. The Python parser/serializer is well-structured with proper error handling, dataclasses, and validation. One issue: 'hello_world' is 11 characters but the username_len field says 0x000c = 12, which is a discrepancy the response doesn't address (it states username length = 12 but the string is 11 chars). This suggests either a null terminator or the response has " }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 0.65, "brief_justification": "The response is an incomplete fragment of reasoning/scratch work, not a coherent answer. It provides no protocol specification, no parser, no serializer, and doesn't even finish analyzing the first packet. It appears to be raw internal thought process that was accidentally output rather than a completed response." }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 4.55, "brief_justification": "The response shows genuine analytical effort in reverse-engineering the protocol, walking through multiple hypotheses transparently. However, it has significant problems: (1) The response is truncated mid-sentence during Packet 3 analysis, never completing the specification or providing the Python parser/serializer that was explicitly requested. (2) The protocol analysis never reaches a fully confident conclusion - it identifies an inconsistency (hello_world being 11 chars but length field sayin" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 5.15, "brief_justification": "The protocol specification has a critical error. The header format is described as having a uint16 length field, but examining the hex dumps shows the header is actually: 2 bytes magic + 1 byte version/type + 1 byte type/version, not what's described. Specifically, looking at Packet 1: after 4d56 (magic), we have 01 (version?), 00 0c which would be a uint16 = 12, but 'hello_world' is 11 bytes, not 12. The actual structure appears to be: magic(2) + type(1) + username_length as uint16(2) + usernam" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 4.95, "brief_justification": "The protocol reverse-engineering has significant errors. The byte after the flags (position 4) is clearly a length prefix for the following string field, not part of the string itself. For Packet 1, byte 0x0c=12 is the length of 'hello_world' + null terminator (or just the string). The parser incorrectly treats this length byte as part of the username data. Similarly, the 4 bytes before the password (00 00 00 05) represent the password length (5 for 'admin'), not a null terminator plus fixed-siz" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.6, "brief_justification": "The protocol reverse-engineering is perfectly correct: magic bytes 'MV', type byte, reserved byte, 1-byte string length for the first field, the string, then a 4-byte big-endian integer for the second length/value field, followed by the second string/value. All three hex dumps are correctly parsed and verified. The Python implementation is clean, well-structured with dataclasses, includes both parsing and serialization, round-trip verification, error handling, and practical usage examples. The s" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 6.15, "brief_justification": "The protocol specification and parser look well-structured and clearly presented, but there's a critical correctness issue. In Packet 1, after the header (4d 56 01 00), the next byte is 0c (12), not 00 00 00 0c. The username length field appears to be 1 byte, not 4 bytes. The hex '0c' = 12 = length of 'hello_world' (11 chars) — wait, 'hello_world' is 11 characters. Actually 0c = 12 which doesn't match 11. Let me recheck: looking at the hex after header: 0c 68 65 6c 6c 6f 5f 77 6f 72 6c 64 00 00 " }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 5.35, "brief_justification": "The protocol analysis has a critical correctness issue with the field length encoding. Looking at Packet 1: after the 4-byte header (4d 56 01 00), the next byte is 0x0c (12), which is the length of 'hello_world' (11 chars) - wait, that's actually 12 if we look at the hex. Actually 'hello_world' is 11 bytes, but 0x0c = 12. The response claims 4-byte little-endian length fields, but examining Packet 1: bytes at offset 4 are '0c 68 65 6c'. If interpreted as LE uint32, that's 0x6c656800c which is wr" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 2.45, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 4, "brief_justification": "The response cuts off abruptly mid-sentence. It provides a stream-of-consciousness analysis of the first two packets but fails to analyze the third packet, write the protocol specification, or provide the requested Python parser/serializer." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 5.15, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 3.8, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 7.55, "brief_justification": "" }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 6.35, "brief_justification": "" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 8.8, "brief_justification": "Excellent reverse-engineering with accurate protocol specification. The byte-by-byte breakdown is correct, the asymmetric length field sizes (uint16 for username/message, uint32 for password/room_id) are properly identified and explained. The Python parser is well-structured with proper error handling, dataclasses, and both parsing and serialization. Minor issues: the no-op line in serialize_message is acknowledged and cleaned up, and the example output is truncated at the end. The response corr" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 4.35, "brief_justification": "The response gets cut off before completing the analysis and never delivers the promised protocol specification or Python parser/serializer. The analysis work shown is methodical and demonstrates good reverse-engineering thinking, correctly identifying magic bytes, packet type, and cross-referencing packets. However, the core discrepancy (0c vs 11 for 'hello_world') is never resolved, and the response ends mid-sentence without providing the actual deliverables requested: a protocol spec and work" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 1, "brief_justification": "The response is incomplete and incoherent - it appears to be a fragment of internal reasoning/scratchpad rather than a finished answer. No protocol specification was provided, no Python parser/serializer was written, and the response trails off mid-analysis without delivering any usable output." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 8.8, "brief_justification": "The response correctly reverse-engineers the protocol format from the hex dumps, accurately identifying the magic bytes, version, packet type, length field, and payload structures. The protocol specification is clear and well-organized. The Python implementation is clean, well-structured with proper error handling, and includes both parsing and serialization. Minor issue: the HEADER_FMT parsing is slightly off (data[2:5] is only 3 bytes but the format '>BBH' expects 4 bytes - version(1) + type(1" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 5.35, "brief_justification": "The response misidentifies the protocol as null-terminated strings when it's actually length-prefixed (the 0c and 00 00 00 05 bytes are length fields, not null terminators). The parser works by coincidence since the length bytes happen to contain zeros, but the serializer is incorrect - it omits length prefix bytes entirely. The bytes.fromhex() with spaces also fails in Python. The protocol spec is fundamentally wrong, making the serializer produce malformed packets that wouldn't match the origi" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.6, "brief_justification": "The response correctly reverse-engineers the protocol from the hex dumps, accurately identifying the magic bytes, type byte, reserved byte, 1-byte username length, 4-byte big-endian password length, and message structure. The protocol specification table is clear and accurate. The Python implementation is well-structured with dataclasses, proper error handling, round-trip serialization, and working assertions against all three sample packets. The code would actually run and pass all tests. Minor" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 9, "brief_justification": "Excellent response that correctly reverse-engineers the protocol from the hex dumps. The analysis is accurate - correctly identifies the magic bytes, packet types, length-prefixed strings, and big-endian encoding. The protocol specification table is well-structured, the Python implementation is clean and functional using struct module properly, and the hex analysis walkthrough confirms the reasoning. Minor gap: doesn't discuss potential edge cases like malformed packets, truncated data, or bound" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 6.35, "brief_justification": "The response has a significant protocol misinterpretation: room_id in Packet 3 is a raw 4-byte big-endian integer, not a length-prefixed ASCII string. The parser would fail on Packet 3 since '00 00 00 01' as a length prefix would indicate 16MB of data. The endianness analysis of length fields is also questionable. The code structure, documentation, and serializer design are good, but the core protocol reverse-engineering contains a critical error that would cause incorrect parsing." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 8.8, "brief_justification": "The response accurately reverse-engineers the protocol from the given packets, provides clear tables and offset specifications, and includes a mostly correct, well-structured Python parser/serializer with error handling. Minor issues include slight offset inaccuracies in the text spec (e.g., login offsets) and a leftover no-op in the first serialize_message, but these are minor and corrected later." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 2.05, "brief_justification": "The response is incomplete, incorrect, and does not provide the requested protocol specification or Python parser. It only starts analyzing the first few bytes without reaching any conclusions or delivering working code." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 4.25, "brief_justification": "The response contains multiple incorrect field layouts, inconsistent length interpretations, and fails to produce a working parser or clean spec. It never resolves the length discrepancies and leaves the analysis unfinished." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 5.55, "brief_justification": "The parser fails to correctly parse the provided packets due to incorrect assumptions about field lengths and offsets (e.g. hard-coded 4-byte password, missing length prefixes). It does not match the actual structure evident in the hex dumps (length-prefixed strings + 4-byte values). The spec is partially correct on magic/header but wrong on details." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 7.5, "brief_justification": "The parser and spec are mostly correct but contain a critical bug: the provided hex dumps show a 1-byte password length for login packets, while the spec and code use a 4-byte u32_be length. This causes parsing failures on the given samples despite the test code claiming success. The rest of the structure, documentation, and code quality are excellent." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.8, "brief_justification": "The response accurately reverse-engineers the protocol from the hex dumps, provides a clear specification with tables, and includes a correct, well-structured Python parser/serializer that handles the given packets. Minor issue: the spec description for Login incorrectly lists 'Username Length' before noting the actual packet starts with username length after header, but code and analysis match the data perfectly." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 5.55, "brief_justification": "The parser has a critical error in length prefix endianness (uses little-endian but packets use big-endian), causing it to fail on all provided packets. The spec incorrectly claims a 4-byte length prefix when packets actually use 1-byte lengths for strings and 4-byte big-endian for the room_id integer. The code is well-structured and clear but fundamentally broken for the given data." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9.6, "brief_justification": "Accurate, thorough, and practical with minor clarity improvement needed." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 6.35, "brief_justification": "Detailed analysis but lacks definitive conclusions and parser implementation." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 1.85, "brief_justification": "Incomplete and confusing response with little useful information." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 5.85, "brief_justification": "The response shows effort in reverse-engineering but lacks a clear, final protocol specification and Python parser. The analysis is somewhat confusing and inconsistent." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 9.6, "brief_justification": "Accurate, thorough, and practical with clear structure." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "Highly accurate, thorough, and clear with excellent practical implementation." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.6, "brief_justification": "Accurate protocol specification and well-implemented Python parser with thorough verification." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.6, "brief_justification": "Accurate protocol specification and Python implementation with thorough testing." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 8.8, "brief_justification": "Accurate protocol spec matching the samples, full parser/serializer implementation, clear presentation, good insight into encoding, highly practical." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 4.3, "brief_justification": "The answer provides some analysis of the packet structure but fails to deliver a complete protocol specification or the requested Python parser/serializer, limiting its correctness, completeness, and practical usefulness." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 0.65, "brief_justification": "Response is largely incorrect, incomplete, lacks any protocol spec or parser, and provides minimal, unclear information." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 2.85, "brief_justification": "The answer starts a reasonable analysis but is incomplete, cuts off before finishing the protocol spec and lacks a functional parser, limiting its accuracy and practical value." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 4.35, "brief_justification": "The answer is clearly written and includes a spec and code, but the protocol details are inaccurate (missing length prefixes) and the parser would not correctly handle the provided packets, reducing correctness, completeness, and practical usefulness." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 4.6, "brief_justification": "The answer is clearly written and includes a full parser, but the inferred protocol is incorrect (username length field size mismatches the hex) and thus the implementation would not parse the given packets correctly, limiting its usefulness." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 4.3, "brief_justification": "The answer is clearly written and includes a spec and code, but the protocol description and parser are incorrect for the given packets (e.g., wrong length prefixes and integer encoding), making it inaccurate and of limited practical use." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 10, "brief_justification": "The model correctly identified the protocol structure, including the magic bytes, packet types, and the use of big-endian integers for lengths and IDs. The Python code is robust, handles errors, and accurately implements both parsing and serialization." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 1.65, "brief_justification": "The response is an incomplete fragment of a thought process. It fails to provide the protocol specification, the parser, or the serializer requested." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 6.85, "brief_justification": "The analysis is excellent and correctly identifies the field structures, including the tricky null-terminator in the first packet. However, the response is incomplete; it cuts off mid-sentence during the analysis of Packet 3 and fails to provide the requested Python parser/serializer and the full protocol specification." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 10, "brief_justification": "The model perfectly reverse-engineered the protocol from the hex dumps, correctly identifying the header structure, the length-prefixed strings, and the big-endian integers. The Python implementation is robust, clean, and includes both parsing and serialization as requested." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 7.35, "brief_justification": "The model correctly identifies the magic bytes, packet types, and string encoding. However, it fails to recognize the length-prefix bytes (0x0c, 0x08, 0x05) present in the hex dumps, misidentifying them as part of the strings or null terminators. This leads to a parser that would fail on the provided hex dumps because it expects null-terminated strings where the data actually uses length-prefixed fields." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 10, "brief_justification": "The model perfectly reverse-engineered the protocol, correctly identifying the magic bytes, type field, reserved byte, and the specific length-prefixing logic (8-bit for first string, 32-bit for second field). The Python code is high-quality, includes a full test suite that validates against the provided hex dumps, and is ready for production use." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 10, "brief_justification": "The model perfectly reverse-engineered the protocol. It correctly identified the magic bytes, packet types, and the little-endian 32-bit length-prefixed fields. It also correctly deduced that the integer room_id was stored as a length-prefixed string representation. The Python code is robust, well-structured, and includes a full test suite that validates against the provided hex dumps." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 8.8, "brief_justification": "Accurate protocol reverse-engineering with correct big-endian integer encoding, proper field sizes, and working Python parser/serializer. Well-organized with tables and clear code structure. Minor: response appears slightly truncated at end but includes essential content." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 4.2, "brief_justification": "Analysis shows good initial effort identifying magic bytes and packet types, but response is severely incomplete - cuts off mid-sentence without providing protocol specification or parser code. Multiple contradictory theories presented without resolution. Packet 3 not analyzed. No actionable output." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 1, "brief_justification": "Response is severely incomplete - only contains fragmented partial analysis with no protocol specification or Python parser provided." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 5.15, "brief_justification": "Good analytical process showing how to reverse-engineer the protocol, correctly identifying magic bytes, packet types, and field layouts. However, the response is incomplete - it cuts off mid-analysis of Packet 3 and never provides the actual Python parser/serializer code that was explicitly requested. The protocol specification is partially derived but not cleanly summarized." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.55, "brief_justification": "Excellent response with accurate protocol specification, complete Python implementation with serialization/deserialization, clear tables and explanations, insightful details about endianness and wire format, and highly practical code with tests and usage examples. Minor note: username length shows 12 but 'hello_world' is 11 chars - may be a typo in the original problem but doesn't affect the correct implementation." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.8, "brief_justification": "Accurate protocol reverse-engineering with correct magic number, packet types, and big-endian encoding. Well-structured specification with tables and complete Python implementation for both parsing and serialization. Clear hex analysis demonstrates understanding. Minor deduction for not explicitly handling all three packets in verification, but core functionality is solid." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.6, "brief_justification": "Accurate protocol reverse-engineering with correct magic bytes, type codes, and little-endian length-prefix field structure. Complete specification tables and full Python implementation with both parser and serializer. Clear documentation and working test code demonstrating round-trip parsing." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9, "brief_justification": "Excellent reverse engineering. The protocol specification is accurate and the parser is robust with proper error handling. The only minor deduction is for a small typo in the explanation of the message packet structure (referring to 'message_len' as uint32 in text while code uses uint16)." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 6.75, "brief_justification": "Analysis shows logical inconsistencies in length fields, but provides a structured approach and partial protocol spec. Parser not fully implemented." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 2.85, "brief_justification": "Response is incomplete, incorrect, and lacks a parser or specification; it only shows partial analysis with confusion." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 5.85, "brief_justification": "Analysis contains logical inconsistencies and fails to resolve the length field discrepancy, leading to an incomplete and unclear protocol specification." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 9.35, "brief_justification": "The response correctly identifies the protocol structure, including the magic bytes, version, type, and payload format. It provides a complete, working Python implementation with both parsing and serialization, including error handling and round-trip verification. The code is clean, well-structured, and directly addresses the prompt requirements." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "The response correctly identifies the protocol structure including magic bytes, packet type, flags, and variable/fixed length fields. The parser implementation is accurate and handles the provided examples correctly. The specification is clear and well-structured. The only minor issue is that the parser doesn't explicitly handle the length bytes (0c, 08, 05) that appear to precede the null-terminated strings in the hex dumps, though the parsing logic still works by finding null terminators. The " }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.55, "brief_justification": "Accurate protocol spec, complete parser with serialization, clear structure, insightful analysis of endianness and string handling, highly actionable code." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.6, "brief_justification": "Accurate protocol reverse-engineering with clear specification and functional Python parser; minor omission of Packet 2 verification." } ], "meta": { "source": "The Multivac (app.themultivac.com)", "methodology": "10x10 blind peer matrix evaluation", "criteria": "correctness, completeness, clarity, depth, usefulness", "self_judgments": "excluded from rankings", "license": "Open data — cite as: The Multivac (2026)" } }