{
  "evaluation_id": "EVAL-20260402-133517",
  "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": "2026-04-02T13:35:17.096Z",
  "display_date": "Apr 02, 2026",
  "winner": {
    "name": "GPT-5.4",
    "provider": "openrouter",
    "score": 9.19
  },
  "avg_score": 6.0277777,
  "matrix_size": 71,
  "models_used": [
    {
      "id": "mimo_v2_flash",
      "name": "MiMo-V2-Flash",
      "provider": "Xiaomi"
    },
    {
      "id": "grok_420",
      "name": "Grok 4.20",
      "provider": "openrouter"
    },
    {
      "id": "gemini_3_flash",
      "name": "Gemini 3 Flash Preview",
      "provider": "Google"
    },
    {
      "id": "minimax_m25",
      "name": "MiniMax M2.5",
      "provider": "openrouter"
    },
    {
      "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": "deepseek_v4",
      "name": "DeepSeek V4",
      "provider": "openrouter"
    },
    {
      "id": "gpt_5_4",
      "name": "GPT-5.4",
      "provider": "openrouter"
    }
  ],
  "rankings": {
    "gpt_5_4": {
      "display_name": "GPT-5.4",
      "provider": "openrouter",
      "average_score": 9.19,
      "score_count": 8,
      "min_score": 8.3,
      "max_score": 10,
      "rank": 1
    },
    "mimo_v2_flash": {
      "display_name": "MiMo-V2-Flash",
      "provider": "Xiaomi",
      "average_score": 6.87,
      "score_count": 9,
      "min_score": 3.95,
      "max_score": 9,
      "rank": 2
    },
    "deepseek_v4": {
      "display_name": "DeepSeek V4",
      "provider": "openrouter",
      "average_score": 6.81,
      "score_count": 8,
      "min_score": 4.35,
      "max_score": 10,
      "rank": 3
    },
    "grok_420": {
      "display_name": "Grok 4.20",
      "provider": "openrouter",
      "average_score": 6.64,
      "score_count": 8,
      "min_score": 3.35,
      "max_score": 9.55,
      "rank": 4
    },
    "gemini_3_flash": {
      "display_name": "Gemini 3 Flash Preview",
      "provider": "Google",
      "average_score": 6.54,
      "score_count": 8,
      "min_score": 4.2,
      "max_score": 8.8,
      "rank": 5
    },
    "minimax_m25": {
      "display_name": "MiniMax M2.5",
      "provider": "openrouter",
      "average_score": 6.33,
      "score_count": 9,
      "min_score": 3.25,
      "max_score": 8.95,
      "rank": 6
    },
    "claude_opus_46": {
      "display_name": "Claude Opus 4.6",
      "provider": "openrouter",
      "average_score": 4.84,
      "score_count": 8,
      "min_score": 2.25,
      "max_score": 7.35,
      "rank": 7
    },
    "claude_sonnet_46": {
      "display_name": "Claude Sonnet 4.6",
      "provider": "openrouter",
      "average_score": 4.26,
      "score_count": 6,
      "min_score": 1.45,
      "max_score": 8.2,
      "rank": 8
    },
    "gemini_31_pro": {
      "display_name": "Gemini 3.1 Pro",
      "provider": "openrouter",
      "average_score": 2.77,
      "score_count": 7,
      "min_score": 0.65,
      "max_score": 5,
      "rank": 9
    }
  },
  "judgments": [
    {
      "judge_key": "gemini_31_pro",
      "judge_name": "Gemini 3.1 Pro",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 5.2,
      "brief_justification": ""
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 9.25,
      "brief_justification": "Accurate, thorough, and practical with clear structure."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 8.8,
      "brief_justification": "Accurate protocol analysis and thorough Python implementation with clear structure and practical value."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 8.6,
      "brief_justification": "Accurate protocol specification and clear Python implementation."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 8.8,
      "brief_justification": "Thorough and accurate analysis with clear structure and practical implementation."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 2.25,
      "brief_justification": "The response mostly contains unresolved reasoning and stops before giving a final protocol spec or Python parser/serializer. It identifies some likely structure correctly, but leaves key ambiguity unresolved and does not fulfill the requested implementation."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 0.65,
      "brief_justification": "The response is truncated and incomplete. It begins identifying the protocol but does not finish the analysis, provide a full specification, or include the requested Python parser/serializer."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "claude_sonnet_46",
      "respondent_name": "Claude Sonnet 4.6",
      "weighted_score": 1.45,
      "brief_justification": "The response never reaches a coherent protocol specification or provides the requested Python parser/serializer. It identifies the basic magic/type idea but remains confused by lengths, ends mid-analysis, and is not actionable."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 3.35,
      "brief_justification": "Well-structured, but the inferred protocol is largely incorrect. The dumps indicate type is likely at byte 3 and lengths are not u16-be as claimed; the parser/serializer does not actually match Packet 1 or Packet 3. It is clear and includes code, but the code would fail on the provided samples, limiting practical usefulness."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 4.35,
      "brief_justification": "Well-structured and readable, but the core reverse-engineering is mostly wrong: it invents 2-byte little-endian length fields and 4-byte alignment that do not match the dumps. The examples indicate 1-byte string lengths followed directly by data, then a 4-byte big-endian integer for password length/room_id. Parser/serializer therefore would not correctly parse or reproduce the given packets."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 5.15,
      "brief_justification": "Well-structured and readable, but it misidentifies the field size at offset 4 as 4 bytes instead of 2 bytes shown in the dumps, then invents an inconsistency in the prompt and builds the parser around the wrong format. This materially hurts correctness and practical usefulness despite decent explanation and coverage."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 3.25,
      "brief_justification": "The inferred format is partly wrong: command is not little-endian uint16 as stated, and the string length fields are mis-sized (examples indicate 2-byte lengths, not 1-byte). The Python implementation is also truncated and therefore unusable, though the presented structure is somewhat clear."
    },
    {
      "judge_key": "gpt_5_4",
      "judge_name": "GPT-5.4",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 3.95,
      "brief_justification": "The response analyzes the packets clearly, but it misidentifies the string length field size: the dumps show a 1-byte length for username/message, not a 4-byte length. It also inconsistently claims all strings are 4-byte length-prefixed, which contradicts the packet bytes. The parser is incomplete and cut off, so the requested parser/serializer is not fully delivered."
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "gpt_5_4",
      "respondent_name": "GPT-5.4",
      "weighted_score": 8.3,
      "brief_justification": "The reverse-engineering is mostly correct and well-presented, but there's an issue with the username length field. For Packet 1, `00 0c` = 12, but 'hello_world' is 11 characters, not 12. The hex dump shows only 11 bytes (68 65 6c 6c 6f 5f 77 6f 72 6c 64) between the length field and the password length. This means the interpretation of username_len as uint16 BE giving 12 is incorrect - it doesn't match the actual data. The parser would fail on the actual hex data since it would try to read 12 by"
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "claude_sonnet_46",
      "respondent_name": "Claude Sonnet 4.6",
      "weighted_score": 2.5,
      "brief_justification": "The response shows extensive working-out of the protocol analysis but never reaches a definitive conclusion. It gets stuck in a loop trying to reconcile the username length discrepancy in packet 1 (0x0c=12 vs 'hello_world'=11 chars) and never produces a final protocol specification or a working Python parser/serializer as requested. The response appears truncated mid-sentence. While the analytical process demonstrates some understanding of binary protocol concepts, the lack of any final answer, "
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 6.3,
      "brief_justification": "The protocol specification has a critical error: the username length field is described as u16-be but examining Packet 1, byte offset 4 is 0x00 0x0c which would give length 12 for 'hello_world' (11 chars). Actually looking more carefully: after the header 4d 56 01 00, the next byte is 0c (12), not 00 0c. The field appears to be a single byte (0x0c = 12), but 'hello_world' is 11 characters. This doesn't match u16-be either since 00 0c = 12 ≠ 11. The response claims u16-be with value 0x000c=12, bu"
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 5.75,
      "brief_justification": "The protocol analysis has a significant error in the first field length interpretation. Looking at Packet 1: byte 4 is 0x0c (12), which matches 'hello_world' length (11) only if interpreted as a single byte, not a 2-byte little-endian value (0x000c would be bytes 4-5, but byte 5 is 0x68 which is 'h'). The correct interpretation is that byte 4 is a single-byte length field for the username, not a 2-byte field. With a 2-byte length field reading 0x000c from bytes 4-5 in little-endian, byte 4=0x0c "
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 5.95,
      "brief_justification": "The response has a significant correctness issue. Looking at Packet 1: after the magic bytes (4d 56), cmd (01), reserved (00), the next bytes are 0c, not 00 00 00 0c. The original hex dump shows the length field as a 2-byte value (00 0c = 12), not a 4-byte value. The response acknowledges this inconsistency but then changes the actual packet data to fit a 4-byte assumption, which contradicts the given hex dumps. With 4-byte lengths, the packets would be longer than shown. The parser code won't c"
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 6.9,
      "brief_justification": "The protocol specification is mostly correct - magic bytes, command field, and payload structure are accurately reverse-engineered. However, the specification says command is little-endian uint16 but 01 00 could also be big-endian with a zero high byte - this is a minor ambiguity. The password length field is described as uint32 but the bytes 00 00 00 05 for length 5 are actually big-endian, contradicting the 'all integers are little-endian' claim. The username length is correctly identified as "
    },
    {
      "judge_key": "claude_opus_46",
      "judge_name": "Claude Opus 4.6",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 6.05,
      "brief_justification": "The analysis is well-structured and clearly presented, but contains a critical error: the username length field in the hex dumps is 1 byte (0x0c for 12, 0x08 for 8, 0x05 for 5), not 4 bytes. The specification incorrectly states all length-prefixed strings use a 4-byte length prefix, which contradicts the actual hex data (e.g., 'hello_world' is 11 chars but 0x0c=12 is used as 1-byte length, suggesting a null terminator or off-by-one issue that isn't addressed). Additionally, the Python parser cod"
    },
    {
      "judge_key": "gemini_31_pro",
      "judge_name": "Gemini 3.1 Pro",
      "respondent_key": "gpt_5_4",
      "respondent_name": "GPT-5.4",
      "weighted_score": 9.8,
      "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": 4.05,
      "brief_justification": "The response cuts off prematurely, providing only a partial analysis and completely failing to deliver the requested protocol specification and Python code."
    },
    {
      "judge_key": "gemini_31_pro",
      "judge_name": "Gemini 3.1 Pro",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 5.35,
      "brief_justification": ""
    },
    {
      "judge_key": "gemini_31_pro",
      "judge_name": "Gemini 3.1 Pro",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 5.75,
      "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": 6.3,
      "brief_justification": ""
    },
    {
      "judge_key": "gemini_31_pro",
      "judge_name": "Gemini 3.1 Pro",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 4.25,
      "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": 9,
      "brief_justification": "Excellent reverse-engineering work. The hex dump analysis is accurate and correctly identifies magic bytes, packet types, field sizes, and endianness. The protocol spec tables are clear and well-structured. The Python parser/serializer is robust with proper error handling, bounds checking, and round-trip verification. The honest note about the asymmetric length field sizes (uint16 vs uint32) shows good analytical thinking. Minor deduction: could have explored whether the inconsistent length fiel"
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 5.6,
      "brief_justification": "The response shows strong analytical reasoning and careful byte-by-byte analysis, correctly identifying magic bytes, message types, and field structures. However, the response is incomplete - it cuts off mid-analysis without ever delivering the promised protocol specification or Python parser/serializer. The working-through of contradictions is intellectually honest and demonstrates good reverse engineering methodology, but the core deliverables (spec + parser) are entirely missing, making it pr"
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 1.45,
      "brief_justification": "The response is severely truncated, cutting off mid-sentence during the analysis. It begins to break down the first packet but provides no complete protocol specification, no parser, no serializer, and no meaningful analysis. The response is essentially incomplete and unusable."
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 5.55,
      "brief_justification": "The response has good structure, clear code, and solid error handling, but contains critical correctness errors: the Login packet type byte is 0x00 not 0x01, and the length fields for password/message appear to be 4-byte u32 not 2-byte u16 (evidenced by '00 00 00 05' for password length). These errors mean the parser would fail to correctly parse the provided example packets, and the round-trip test would not pass as claimed."
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 5.95,
      "brief_justification": "The response has a critical correctness flaw: it incorrectly identifies the username/message length field as a 2-byte little-endian short (struct '<H'), when the hex dumps show it's a single byte (0x0c=12 for 'hello_world' at offset 4, with byte 5 being 0x68='h'). This means the parser would fail on actual packets. The protocol spec also incorrectly describes the length field. The code structure, padding logic, and overall organization are good, but the fundamental field-width error makes the pa"
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 4.8,
      "brief_justification": "The response misidentifies the string length fields as 4-byte integers when they are actually 1-byte values (0x0c=12, 0x08=8, 0x05=5). The parser would fail on the actual provided packets. The response even acknowledges an 'inconsistency' and modifies the test hex dumps to add non-existent padding bytes rather than correcting the field size assumption. The structure, clarity, and approach are good, but the core protocol analysis is wrong."
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 7,
      "brief_justification": "The protocol specification is well-reasoned and mostly correct based on the hex dumps. The table format is clear and readable. However, the response is cut off mid-implementation, missing the full Python parser/serializer code including parse_packet, login, and message functions. The spec correctly identifies magic bytes, command field, and payload structure. One minor issue: the command field endianness assumption (little-endian) is stated but the bytes 01 00 and 02 00 do support little-endian "
    },
    {
      "judge_key": "claude_sonnet_46",
      "judge_name": "Claude Sonnet 4.6",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 8.1,
      "brief_justification": "The response correctly reverse-engineers the protocol with accurate byte-by-byte analysis, proper identification of magic bytes, packet types, flags, and length-prefixed strings. The protocol specification is well-structured and accurate. The Python implementation is well-designed with good use of dataclasses and struct module. However, the response is cut off mid-implementation - the parser class is incomplete, missing the _unpack_length_prefixed_string method body, the main parse method, and e"
    },
    {
      "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 hex dumps, correctly identifies the header and variable-length string formats (with differing length prefixes), provides a clean spec table, and includes a robust, well-structured Python parser/serializer with error handling that matches the samples and expected output. Minor deduction for depth as it doesn't explore potential additional fields or edge cases beyond the given samples."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 4.8,
      "brief_justification": "The response performs a detailed byte-by-byte analysis but reaches incorrect conclusions about the protocol (e.g. uint16 length including null for username in packet 1, uint32 for password). It never resolves the format or produces the requested parser/serializer, leaving the task incomplete."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 3.25,
      "brief_justification": "The response is incomplete and only begins the analysis without providing the full protocol spec or any code. It fails to deliver the requested parser/serializer."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "claude_sonnet_46",
      "respondent_name": "Claude Sonnet 4.6",
      "weighted_score": 4.5,
      "brief_justification": "The response identifies the magic bytes and packet types correctly but fails to converge on a consistent, correct protocol structure. It spends most of its length on contradictory length-field theories without resolving the 0x0c vs 11-byte username issue or noticing the 4-byte big-endian length for the password field that appears in both packets. No actual parser or serializer code is provided, making it low on usefulness and completeness."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 5.35,
      "brief_justification": "The parser and spec do not match the provided packet hex dumps. Length fields and padding logic are incorrect (e.g. username length is not a 2-byte LE int at offset 4, padding is not to 4-byte boundary after username). Serializer produces different bytes than input packets. Code runs but fails to correctly reverse-engineer the actual format."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 4.8,
      "brief_justification": "Protocol spec is incorrect (wrong field order/sizes compared to hex dumps). Parser is incomplete (truncated code)."
    },
    {
      "judge_key": "grok_420",
      "judge_name": "Grok 4.20",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 8.45,
      "brief_justification": "The response accurately reverse-engineers the protocol from the given packets, provides a clear structured specification with tables, and includes a mostly complete and correct Python parser/serializer implementation. Minor issues: the parser class is cut off mid-method, and the length prefix for strings is shown as 4 bytes in the spec but the initial analysis text incorrectly labels the first length as a 1-byte field (0x0c)."
    },
    {
      "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 protocol specification and thorough Python implementation with clear explanations."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 7.35,
      "brief_justification": "Detailed analysis but contains some contradictions and unresolved questions about the protocol format."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 5,
      "brief_justification": "Incomplete analysis and missing parser implementation."
    },
    {
      "judge_key": "deepseek_v4",
      "judge_name": "DeepSeek V4",
      "respondent_key": "claude_sonnet_46",
      "respondent_name": "Claude Sonnet 4.6",
      "weighted_score": 5.45,
      "brief_justification": "Struggles with consistent protocol interpretation and lacks clear structure."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "gpt_5_4",
      "respondent_name": "GPT-5.4",
      "weighted_score": 9.05,
      "brief_justification": "Accurately matches all sample packets, fully specifies both packet types, provides clear tables and well‑structured Python code, offers insightful notes on length field inconsistencies, and includes ready‑to‑use parsing/serialization functions."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 3.85,
      "brief_justification": "The answer provides a partial analysis of the packet structure but stops short of delivering a full protocol specification or 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": 2.85,
      "brief_justification": "The answer starts to outline the protocol but is cut off, lacking a full specification, parser, and serializer, making it largely incomplete and of limited practical value."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 5.15,
      "brief_justification": "The answer is clearly written and includes a full parser, but the protocol spec mismatches the given packet structure (field order and length encoding), reducing factual accuracy and practical utility."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 4.2,
      "brief_justification": "The answer misidentifies the length field size and null handling, leading to an inaccurate protocol spec and a parser that won't correctly parse the given packets. It is clearly presented and discusses some aspects, but lacks accurate coverage and practical utility."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 4.6,
      "brief_justification": "Spec is clear but misrepresents observed null terminators and omits handling them; code is incomplete and thus not fully functional, limiting usefulness despite decent presentation."
    },
    {
      "judge_key": "gpt_oss_120b",
      "judge_name": "GPT-OSS-120B",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 4.2,
      "brief_justification": "The answer explains the packet structure clearly but misinterprets the length fields (username uses 1-byte length, not 4-byte) and provides an incomplete Python parser, reducing factual accuracy and practical utility."
    },
    {
      "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 perfectly reverse-engineered the protocol, identifying the specific field lengths (uint16 for strings, uint32 for password/room_id) which were inconsistent but present in the source data. The Python code is robust, includes error handling, and provides both parsing and serialization."
    },
    {
      "judge_key": "gemini_3_flash",
      "judge_name": "Gemini 3 Flash Preview",
      "respondent_key": "claude_opus_46",
      "respondent_name": "Claude Opus 4.6",
      "weighted_score": 4.05,
      "brief_justification": "The model failed to complete the task. It provided a thought process for reverse engineering but stopped abruptly without providing the protocol specification or the Python parser/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": 3.45,
      "brief_justification": "The response is incomplete and fails to provide the requested protocol specification or the Python parser/serializer. It consists only of a stream-of-consciousness analysis that ends abruptly without reaching a conclusion or fulfilling the prompt's requirements."
    },
    {
      "judge_key": "gemini_3_flash",
      "judge_name": "Gemini 3 Flash Preview",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 9.55,
      "brief_justification": "The model correctly reverse-engineered the protocol, identifying the magic bytes, version, type, and length-prefixed strings. The Python code is robust, includes error handling, and successfully passes a round-trip test."
    },
    {
      "judge_key": "gemini_3_flash",
      "judge_name": "Gemini 3 Flash Preview",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 10,
      "brief_justification": "The model perfectly reverse-engineered the protocol, identifying the 4-byte alignment/padding requirement which is the most subtle part of the challenge. The Python code is clean, functional, and includes both parsing and serialization."
    },
    {
      "judge_key": "gemini_3_flash",
      "judge_name": "Gemini 3 Flash Preview",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 8.95,
      "brief_justification": "The reverse-engineering of the binary protocol is perfectly accurate based on the provided hex dumps. The specification is clear and correctly identifies the field types and endianness. However, the Python implementation is incomplete, cutting off mid-sentence/mid-code, which reduces its immediate usefulness."
    },
    {
      "judge_key": "gemini_3_flash",
      "judge_name": "Gemini 3 Flash Preview",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 9,
      "brief_justification": "The model correctly identifies the protocol structure, including the magic number, packet types, and big-endian length-prefixed strings. It provides a clear specification and a well-structured Python implementation, although the parser code is slightly truncated at the very end."
    },
    {
      "judge_key": "minimax_m25",
      "judge_name": "MiniMax M2.5",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 1.9,
      "brief_justification": "Response is severely incomplete - cuts off mid-sentence after just a few words. No protocol specification, parser, or meaningful analysis provided."
    },
    {
      "judge_key": "minimax_m25",
      "judge_name": "MiniMax M2.5",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 8.8,
      "brief_justification": ""
    },
    {
      "judge_key": "minimax_m25",
      "judge_name": "MiniMax M2.5",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 8.55,
      "brief_justification": "Accurate protocol analysis with correct identification of magic number, command IDs, and structure. Minor inconsistency in handling single-byte vs 4-byte length fields, but overall correct. Well-documented table and functional Python parser with serialize/parse methods."
    },
    {
      "judge_key": "minimax_m25",
      "judge_name": "MiniMax M2.5",
      "respondent_key": "mimo_v2_flash",
      "respondent_name": "MiMo-V2-Flash",
      "weighted_score": 8.1,
      "brief_justification": "Accurate protocol reverse-engineering with clear analysis and well-structured code. The serializer is complete and correct, but the parser implementation is cut off/incomplete, reducing practical usefulness."
    },
    {
      "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": "Accurate reverse-engineering, thorough spec, clear code, and practical parser with examples."
    },
    {
      "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 interpretation, but provides a structured approach and partial protocol specification."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "gemini_31_pro",
      "respondent_name": "Gemini 3.1 Pro",
      "weighted_score": 4.3,
      "brief_justification": "Response is incomplete and stops mid-analysis; lacks protocol specification and parser code, making it only partially correct and not useful."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "claude_sonnet_46",
      "respondent_name": "Claude Sonnet 4.6",
      "weighted_score": 8.2,
      "brief_justification": "The response correctly identifies the core structure (magic bytes, type, length-prefixed strings) and provides a working parser. The confusion around null terminators in the analysis is a minor deduction, but the final implementation handles it correctly by stripping nulls."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "grok_420",
      "respondent_name": "Grok 4.20",
      "weighted_score": 8.6,
      "brief_justification": "Accurate protocol deduction and functional parser; minor oversight in packet structure (missing version byte in spec) but overall robust."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "deepseek_v4",
      "respondent_name": "DeepSeek V4",
      "weighted_score": 8.55,
      "brief_justification": "Accurate protocol reverse-engineering with clear specification and functional parser/serializer; minor oversight in padding calculation for password length field."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "gemini_3_flash",
      "respondent_name": "Gemini 3 Flash Preview",
      "weighted_score": 8.55,
      "brief_justification": "Accurate protocol analysis and functional parser, but minor inconsistency in hex dump handling noted."
    },
    {
      "judge_key": "mimo_v2_flash",
      "judge_name": "MiMo-V2-Flash",
      "respondent_key": "minimax_m25",
      "respondent_name": "MiniMax M2.5",
      "weighted_score": 8.6,
      "brief_justification": "Accurate protocol spec and parser, but incomplete code snippet and minor oversight in length fields."
    }
  ],
  "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)"
  }
}