{ "evaluation_id": "EVAL-20260402-134400", "question_id": "CODE-017", "question_text": "This Go code processes orders concurrently but occasionally produces incorrect totals. Find and fix all concurrency issues.\n\n```go\npackage main\n\nimport (\n \"fmt\"\n \"sync\"\n)\n\ntype OrderProcessor struct {\n totalRevenue float64\n orderCount int\n errors []string\n}\n\nfunc (op *OrderProcessor) ProcessOrder(amount float64, wg *sync.WaitGroup) {\n defer wg.Done()\n \n if amount <= 0 {\n op.errors = append(op.errors, fmt.Sprintf(\"invalid amount: %.2f\", amount))\n return\n }\n \n op.totalRevenue += amount\n op.orderCount++\n}\n\nfunc main() {\n op := &OrderProcessor{}\n var wg sync.WaitGroup\n \n orders := []float64{99.99, 149.50, -10.00, 299.99, 49.99, 0, 199.99}\n \n for _, amount := range orders {\n wg.Add(1)\n go op.ProcessOrder(amount, &wg)\n }\n \n wg.Wait()\n fmt.Printf(\"Total: $%.2f from %d orders\\n\", op.totalRevenue, op.orderCount)\n}\n```", "category": "code", "timestamp": "2026-04-02T13:44:00.096Z", "display_date": "Apr 02, 2026", "winner": { "name": "GPT-OSS-120B", "provider": "OpenAI", "score": 9.75 }, "avg_score": 9.019, "matrix_size": 89, "models_used": [ { "id": "gpt_oss_120b", "name": "GPT-OSS-120B", "provider": "OpenAI" }, { "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": "grok_420", "name": "Grok 4.20", "provider": "openrouter" }, { "id": "deepseek_v4", "name": "DeepSeek V4", "provider": "openrouter" }, { "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": 9.75, "score_count": 9, "min_score": 9, "max_score": 10, "rank": 1 }, "gpt_5_4": { "display_name": "GPT-5.4", "provider": "openrouter", "average_score": 9.49, "score_count": 9, "min_score": 8.8, "max_score": 10, "rank": 2 }, "claude_opus_46": { "display_name": "Claude Opus 4.6", "provider": "openrouter", "average_score": 9.46, "score_count": 8, "min_score": 8.8, "max_score": 10, "rank": 3 }, "claude_sonnet_46": { "display_name": "Claude Sonnet 4.6", "provider": "openrouter", "average_score": 9.4, "score_count": 9, "min_score": 9, "max_score": 10, "rank": 4 }, "grok_420": { "display_name": "Grok 4.20", "provider": "openrouter", "average_score": 9.12, "score_count": 9, "min_score": 8.55, "max_score": 10, "rank": 5 }, "mimo_v2_flash": { "display_name": "MiMo-V2-Flash", "provider": "Xiaomi", "average_score": 9.02, "score_count": 9, "min_score": 7.95, "max_score": 9.8, "rank": 6 }, "minimax_m25": { "display_name": "MiniMax M2.5", "provider": "openrouter", "average_score": 8.96, "score_count": 9, "min_score": 8.4, "max_score": 9.8, "rank": 7 }, "gemini_3_flash": { "display_name": "Gemini 3 Flash Preview", "provider": "Google", "average_score": 8.91, "score_count": 9, "min_score": 8.4, "max_score": 9.8, "rank": 8 }, "deepseek_v4": { "display_name": "DeepSeek V4", "provider": "openrouter", "average_score": 8.79, "score_count": 9, "min_score": 8, "max_score": 9.8, "rank": 9 }, "gemini_31_pro": { "display_name": "Gemini 3.1 Pro", "provider": "openrouter", "average_score": 7.29, "score_count": 9, "min_score": 4.05, "max_score": 9.6, "rank": 10 } }, "judgments": [ { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 10, "brief_justification": "The response accurately identifies all concurrency issues, provides a complete and correct fix with a mutex, includes a test and verification steps, and offers practical advice." }, { "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 identification of race conditions and correct fix with mutex; comprehensive explanation and practical code." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9, "brief_justification": "Accurate identification of data races and correct fix with mutex; thorough coverage and clear explanation; minor deduction for not mentioning potential deadlock risks with nested locks." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 9, "brief_justification": "Accurately identifies all shared-state races and provides a correct mutex-based fix with clear explanation. Well-structured and practical, though it could mention alternative designs like locking only around shared-state updates or collecting results via channels." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 4.05, "brief_justification": "Correctly identifies the main data races and proposes a mutex, but the response is truncated, incomplete, and does not fully provide the fixed program or mention additional best practices like protecting reads if accessed concurrently or using the race detector." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9, "brief_justification": "Accurately identifies the real shared-state races and provides a solid mutex-based fix with clear explanation. Very clear and practical. Minor overstatement: reading after wg.Wait() is already safe because Wait establishes completion before main reads, so Summary lock is good encapsulation but not strictly required for correctness here." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 8.55, "brief_justification": "Accurately identifies the key races and provides solid fixes with mutexes and an atomic alternative. Clear and practical, though it slightly overstates slice-append consequences and mentions panic due to concurrent map/slice operations even though no map is involved and slice races are undefined behavior rather than a specific guaranteed panic." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "Accurately identifies the shared-state races on revenue, count, and errors, and provides a valid mutex-based fix with clear explanation. Good mention of an atomic alternative, though it is only partial and omits read-side synchronization nuances." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "Accurately identifies all real concurrency issues (races on revenue, count, and errors slice) and provides a correct mutex-based fix with consistent snapshotting, clear explanation, and practical verification steps." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.4, "brief_justification": "Accurately identifies the data races on shared fields and fixes them with a mutex, with clear explanation and correct code. Slightly incomplete because it does not discuss protecting reads consistently or alternative designs like aggregating results via channels." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 8.4, "brief_justification": "Accurately identifies the shared-state races and provides a valid mutex-based fix with race-detector guidance. Clear and practical, though it slightly overstates that reads must be locked in this exact program since they occur after wg.Wait(), and it does not discuss alternative fixes like atomics or aggregating results via channels." }, { "judge_key": "gpt_5_4", "judge_name": "GPT-5.4", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 8.8, "brief_justification": "Accurately identifies the shared-state races on revenue, count, and errors, and fixes them idiomatically with a mutex. The explanation is clear and practical, with correct sample output and useful notes. Minor nit: the memory-visibility discussion is broad, and the atomic note is slightly dated/imprecise." }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all three data races (totalRevenue, orderCount, errors slice), explains why each is problematic, and provides two correct fixed versions—one with a broad lock and one with narrow locking. It also correctly notes that the lock in main() after wg.Wait() is technically unnecessary but demonstrates good practice. The expected output is computed correctly. The suggestion to use `go run -race` and the offer of a channel-based alternative add practical value. The expla" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 8.6, "brief_justification": "The response correctly identifies all three data races (totalRevenue, orderCount, errors slice) and provides the right fix using sync.Mutex. The explanation is clear, the optimization of formatting the error string outside the lock is a nice touch showing deeper understanding. The code appears truncated at the end but the essential fix and explanation are complete. Minor deduction for the truncation and for not mentioning alternative approaches (atomic operations, channels)." }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.8, "brief_justification": "All three race conditions are correctly identified and fixed. The explanation covers why a single mutex is used (transactional consistency), why atomic isn't ideal here, and why channels would be overkill. The Summary() method with slice copy is a nice defensive addition. The table format and design decision callouts make the response exceptionally clear. Minor note: after wg.Wait(), reading fields directly is actually safe due to the happens-before guarantee, so the Summary() lock isn't strictl" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 9.2, "brief_justification": "The response correctly identifies all three data races (totalRevenue, orderCount, errors slice), explains why they're problematic, and provides two well-structured fixes. The mutex-based solution is correct and clean. The atomic-based alternative is a nice addition showing deeper knowledge, though the float-to-cents conversion could lose precision in edge cases (e.g., amount*100 not being exact). The explanation is clear, well-organized, and actionable. Minor nit: after wg.Wait() the reads are s" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "The response correctly identifies all three race conditions (totalRevenue, orderCount, errors slice) and provides a correct fix using sync.Mutex. The explanation is clear and well-structured. The alternative atomic approach is a nice addition showing depth, though the atomic float64 handling via uint64 cents conversion is a bit hand-wavy. Minor deduction for completeness: could have mentioned using defer for unlock consistency or discussed the loop variable capture issue (though in this case the" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all three data races (totalRevenue, orderCount, errors slice), explains why they occur, and provides a fully correct fix using sync.Mutex. The explanation is exceptionally well-structured with tables, code comments, a Snapshot helper for safe reading, a test file with race detector verification, and a concurrency best-practices checklist. The depth is excellent—covering slice copy semantics in Snapshot, the non-deterministic nature of races, and practical verifi" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 9, "brief_justification": "The response correctly identifies all three race conditions (totalRevenue, orderCount, errors slice) and fixes them properly with sync.Mutex. The explanation is exceptionally clear with well-structured sections. The code is correct and idiomatic Go. Minor nit: could have mentioned defer mu.Unlock() as a safer pattern, or discussed using a single lock for the entire function body to simplify, but these are stylistic preferences. The alternative tip about sync/atomic is a nice touch, though atomic" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 8.6, "brief_justification": "The response correctly identifies all three data races and provides a valid fix using sync.Mutex. The table summarizing issues is clear, the fixed code is correct, and the verification step with -race is a nice touch. Minor depth deductions: could have discussed alternative approaches (channels, atomic operations for numeric fields), or noted that locking the entire function reduces concurrency benefits. Could also mention the loop variable capture issue is not present here due to range value se" }, { "judge_key": "claude_opus_46", "judge_name": "Claude Opus 4.6", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.45, "brief_justification": "The response correctly identifies all three concurrency issues (race on totalRevenue, orderCount, and errors slice), explains why each is a problem, and provides a correct fix using sync.Mutex. The explanation of memory visibility, lost updates, and slice header corruption is accurate. The mention of atomic operations as an alternative and the note about float64 limitations adds depth. The fixed code is correct and idiomatic Go. The only minor gap is not mentioning defer for Unlock (a stylistic " }, { "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": "The response accurately identifies all concurrency issues, provides excellent explanations, and offers robust solutions including best practices like narrow locking and using the race detector." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 10, "brief_justification": "The response accurately identifies all concurrency issues, provides a correct and idiomatic fix using sync.Mutex, and offers excellent explanations including design decisions and memory model concepts." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.55, "brief_justification": "The response correctly identifies and fixes the race conditions using a mutex and provides excellent explanations. However, it incorrectly implies that reading fields after wg.Wait() requires synchronization (wg.Wait() establishes a happens-before relationship), though adding a thread-safe Summary method is still good practice." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 9.55, "brief_justification": "Accurately identifies data races and provides excellent solutions, including an atomic alternative. The atomic approach has a minor floating-point truncation risk, but overall the response is highly effective and clear." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 9.8, "brief_justification": "The response accurately identifies all concurrency issues, provides a clear and correct mutex-based solution, and offers an insightful alternative using atomic operations." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 10, "brief_justification": "The response perfectly identifies and fixes the concurrency issues, provides clear explanations, includes a thread-safe way to read the results, and even provides a test case using the race detector." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 9.8, "brief_justification": "The response correctly identifies the race conditions and provides an idiomatic, perfectly working solution using sync.Mutex. The explanation is clear, and the code is ready to use." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.4, "brief_justification": "The response correctly identifies and fixes the data races using a mutex. It is clear and provides verification steps, though it misses discussing the performance implications of locking the entire function." }, { "judge_key": "gemini_31_pro", "judge_name": "Gemini 3.1 Pro", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.8, "brief_justification": "The response accurately identifies all race conditions, provides a correct and idiomatic fix using sync.Mutex, and clearly explains the reasoning. The discussion of atomic operations adds good depth." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all three data races, provides two well-structured fixes (whole-function lock and narrow lock), explains why each issue occurs, shows expected output for verification, mentions the race detector tool, and offers further alternatives. The narrow-lock version even properly copies slice data before releasing the mutex in main. Comprehensive and practically actionable." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all three race conditions (totalRevenue, orderCount, errors slice), provides a clean fix using sync.Mutex, and explains the design decisions thoroughly. The table format aids clarity, the happens-before explanation for the post-Wait read is technically accurate, and the rationale for choosing Mutex over atomics is well-reasoned. The addition of error reporting in main is a nice bonus improvement." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 7.8, "brief_justification": "The response correctly identifies the data race issues and provides a proper mutex-based solution. The explanation is clear and the code demonstrates good practices like minimizing lock contention by formatting strings outside the lock. However, the response is cut off mid-code, missing the rest of main() and any discussion of alternative approaches like sync/atomic for the numeric fields. The core fix is correct and well-explained despite the truncation." }, { "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": "Correctly identifies all three data races, provides two well-structured solutions (mutex and atomic), explains why slices need mutex even in atomic version, and adds error reporting output. Minor note: floating-point to cents conversion can have precision issues, but the response acknowledges this implicitly by using the approach. Overall excellent response." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "The response correctly identifies all three race conditions (totalRevenue, orderCount, and errors slice) and provides a clean mutex-based fix. The alternative atomic approach is a nice addition showing depth, though it correctly notes the limitation with float64 requiring conversion to integer cents. Minor gap: could mention using defer for unlock to prevent potential lock leaks, and the atomic example imports atomic without showing the import statement. Overall very solid and practical response" }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.55, "brief_justification": "The response correctly identifies all three data races (totalRevenue, orderCount, errors slice), provides a well-structured fix using sync.Mutex, adds a Snapshot method for safe reads, includes a test with race detector verification, and provides a practical checklist. The explanation is thorough and well-organized. Minor note: floating point comparison in the test (total != 100) could be fragile, but this is a minor issue in an otherwise excellent response." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.6, "brief_justification": "The response correctly identifies all race conditions and provides a proper fix using sync.Mutex. The explanation is clear and well-structured, covering why the issues occur and what the fix does. The alternative tip about sync/atomic adds useful context. Minor gap: doesn't mention using defer mu.Unlock() as a best practice for panic safety, and doesn't discuss sync/atomic for float64 (which requires workarounds). Overall an excellent, practical response." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 8.4, "brief_justification": "Correctly identifies all three race conditions and fixes them with a mutex. The solution is clean and idiomatic Go. Minor missed opportunity: could mention atomic operations as an alternative for the numeric fields, or channel-based approaches. The lock placement (before validation check) is correct since errors slice also needs protection. Verification command and expected output add practical value." }, { "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 response perfectly identifies all concurrency issues (data races on float, int, and slice), provides two valid ways to fix them using sync.Mutex, explains the logic clearly, and even includes advice on using the Go race detector." }, { "judge_key": "claude_sonnet_46", "judge_name": "Claude Sonnet 4.6", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 8.8, "brief_justification": "The response correctly identifies all three race conditions (totalRevenue, orderCount, errors slice), provides a clean mutex-based fix, and explains the reasoning well. The analysis of memory visibility and the note about atomic operations as an alternative adds good depth. Minor point: the mutex could use defer for unlock to be more idiomatic and safer, but the solution is functionally correct. The expected output is accurate and the explanation is thorough." }, { "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": "Accurately identifies all race conditions with clear explanations, provides multiple correct fixes including best practices like narrow locking and copying data under lock, shows expected output, and suggests detection methods." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 8.8, "brief_justification": "The response accurately identifies all data races, provides a correct fix using mutex protection, explains design choices well, and includes verification steps. Minor deduction for not mentioning that errors are not printed in the original code and could be considered part of the output expectation." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 6.2, "brief_justification": "Identifies the core data race issue correctly and suggests mutex, but the provided code is truncated/incomplete, misses handling errors slice properly, and doesn't address potential issues with error reporting or output." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9, "brief_justification": "The response accurately identifies all race conditions, provides a correct fix using mutex for atomicity and consistency, adds good practices like Summary method and error copying, explains design choices thoroughly with alternatives considered." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.55, "brief_justification": "The response accurately identifies all race conditions (shared fields without synchronization), provides a correct mutex-based fix, and includes a useful alternative with atomics. It also adds error printing which improves the program. Minor issues: doesn't address potential floating-point precision in totals, and the alternative code snippet is incomplete (missing imports and full struct/methods)." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9, "brief_justification": "The response accurately identifies all data races (totalRevenue, orderCount, errors slice), provides a correct fix using mutex for all shared state, adds helpful Snapshot method and test, explains why it works, and includes verification steps. Minor note: the mutex could be finer-grained but the solution is fully correct and thorough." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.6, "brief_justification": "The response correctly identifies the race conditions on shared state and provides a solid mutex-based fix. It is clear, well-structured, and adds useful output for errors. Minor omission of mentioning that errors slice is never printed in original code and that mutex could be held across the if for slightly better style, but overall excellent." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 8.6, "brief_justification": "The response accurately identifies all data races, provides a correct fix using a mutex, includes verification steps, and adds helpful output for errors. Minor deduction as locking the entire method is not the most efficient but is correct and simple." }, { "judge_key": "grok_420", "judge_name": "Grok 4.20", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 8.8, "brief_justification": "The response accurately identifies all race conditions (shared struct fields without synchronization), provides a correct mutex-based fix, explains visibility and atomicity issues, and includes useful enhancements like error printing. Minor deduction for not mentioning that the mutex could be embedded or that finer-grained locking could be used." }, { "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 solution with clear explanations." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 9.05, "brief_justification": "Accurately identifies and fixes concurrency issues with clear, actionable code." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.6, "brief_justification": "Comprehensive and accurate fixes with clear explanations and good design considerations." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 9.6, "brief_justification": "Accurate fixes for all concurrency issues with clear explanations and two alternative solutions." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "Comprehensive, accurate, and actionable with excellent clarity and depth." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 9.25, "brief_justification": "Accurate fix with thorough explanation and practical alternative." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.6, "brief_justification": "Accurate identification and fixes for all concurrency issues with clear explanation and verification steps." }, { "judge_key": "deepseek_v4", "judge_name": "DeepSeek V4", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.2, "brief_justification": "Comprehensive analysis and correct fixes for all concurrency issues, with clear explanations and practical implementation." }, { "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": "Accurately identifies all data races, offers correct mutex-based fixes with clear code, explains lock granularity, provides expected results and race detection guidance, making it highly useful and well-explained." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 9.25, "brief_justification": "Accurately identifies all data races, supplies a correct mutex-based fix, explains design choices, and offers practical code and testing guidance." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 6.6, "brief_justification": "Identifies data races and proposes a mutex, which is correct, but the provided code is incomplete and lacks discussion of alternative approaches, limiting completeness and depth." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.05, "brief_justification": "Accurately identifies all race conditions, supplies correct mutex‑based fix with clear code and thorough explanation, and offers practical improvements." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 8.8, "brief_justification": "Identifies all data races, provides correct mutex‑protected solution and a valid atomic alternative, includes error handling and clear code, offering practical, ready‑to‑use fixes." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "Accurately identifies race conditions and fixes them with a mutex, provides working corrected code, explains alternative atomic method, and presents clear, actionable guidance." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 9.05, "brief_justification": "Accurately identifies race conditions and provides a correct mutex-based fix with clear code and explanation; covers all shared state issues and offers useful guidance, though deeper discussion of alternative patterns could improve depth." }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 8.8, "brief_justification": "" }, { "judge_key": "gpt_oss_120b", "judge_name": "GPT-OSS-120B", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 8.55, "brief_justification": "The answer correctly identifies the race conditions and provides a proper mutex-based fix with clear code and explanations. Minor factual error in the sample output lowers correctness slightly, but overall coverage, clarity, depth, and practical usefulness are strong." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 10, "brief_justification": "The response is perfect. It correctly identifies all three race conditions (including the often-overlooked slice append), provides a clean and idiomatic Go solution using sync.Mutex, and explains the reasoning behind the implementation choices (like why Mutex was used over atomics)." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 9.6, "brief_justification": "The response correctly identifies the data race issues and provides a robust solution using sync.Mutex. It correctly identifies all three shared resources (totalRevenue, orderCount, and the errors slice) that need protection. The code implementation is idiomatic and includes a performance optimization by moving string formatting outside the lock." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 10, "brief_justification": "The response perfectly identifies all three race conditions (revenue, count, and the slice header). It provides a robust fix using a mutex, correctly handles the slice append race, and goes above and beyond by implementing a thread-safe Summary method and explaining why a single lock is superior to atomic operations for consistency." }, { "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 response correctly identifies all concurrency issues, including the subtle race condition on the slice append. It provides a standard Mutex-based solution and an advanced atomic-based solution that correctly handles floating-point precision by converting to cents. The explanation is clear and the code is idiomatic." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all race conditions, including the often-overlooked slice append issue. The provided solution is idiomatic Go and the explanation of atomic limitations with floats adds great depth." }, { "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 response is exceptional. It correctly identifies all three data races (revenue, count, and the slice header/backing array). It provides a robust solution using a Mutex, explains the logic clearly with a table and checklist, and even includes a test case to verify the fix using the Go race detector." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "minimax_m25", "respondent_name": "MiniMax M2.5", "weighted_score": 9.8, "brief_justification": "The response correctly identifies all three race conditions (revenue, count, and the slice append). The provided solution uses a mutex correctly to synchronize access, and the explanation of the fix is clear and actionable." }, { "judge_key": "gemini_3_flash", "judge_name": "Gemini 3 Flash Preview", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 9.8, "brief_justification": "The response perfectly identifies all three concurrency issues (data race on primitives, slice header corruption, and memory visibility). The provided solution is idiomatic Go, correctly implements the Mutex, and includes a helpful explanation of why specific choices were made." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gpt_5_4", "respondent_name": "GPT-5.4", "weighted_score": 9.8, "brief_justification": "Excellent response that correctly identifies all three data races (totalRevenue, orderCount, errors), explains the read-modify-write problem, provides working mutex-based fixes with two approaches, shows expected output, and recommends the race detector. Slightly扣分 for not mentioning sync/atomic as an alternative, but otherwise comprehensive." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 9.25, "brief_justification": "Accurately identifies all three data races (totalRevenue, orderCount, errors slice) and provides correct mutex-based fix. Thorough explanation of design decisions (mutex vs atomic, defer usage, happens-before). Well-structured with clear code and table. Minor completeness gap: could mention -race verification would catch original bug." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 6.1, "brief_justification": "Correctly identifies data races as the core issue and proposes mutex solution, but the response is incomplete - the code snippet is cut off mid-main function. Also lacks discussion of alternative solutions like sync/atomic or channel-based approaches." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.25, "brief_justification": "Accurately identifies all three race conditions and provides a correct mutex-based fix. Thoroughly explains design decisions including why single lock section is needed for consistency, and evaluates alternatives. Well-structured with complete working code." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 8.8, "brief_justification": "Accurately identifies all data race issues on totalRevenue, orderCount, and errors. Provides two correct solutions (mutex and atomic) with working code. Clear structure with explanations of why fixes work. Addresses floating-point atomic limitations. Comprehensive coverage of the concurrency problems." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8, "brief_justification": "Correctly identifies all three race conditions (totalRevenue, orderCount, errors slice) and provides a working mutex-based solution. Well-structured with clear explanations. Minor issues: atomic alternative has implementation problems with float64 handling, and defer should be used for mutex unlock for better practice." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gpt_oss_120b", "respondent_name": "GPT-OSS-120B", "weighted_score": 9.8, "brief_justification": "Thoroughly identifies all three race conditions (totalRevenue, orderCount, errors slice), provides correct mutex-based solution with helpful helper methods, includes verification steps with race detector, and offers best practices checklist. Well-organized and highly actionable." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "gemini_3_flash", "respondent_name": "Gemini 3 Flash Preview", "weighted_score": 8.85, "brief_justification": "Correctly identifies race conditions as the root cause and provides a proper mutex-based fix. The solution is complete, well-explained, and directly actionable. Minor deduction for not covering alternative approaches like channels in more depth." }, { "judge_key": "minimax_m25", "judge_name": "MiniMax M2.5", "respondent_key": "mimo_v2_flash", "respondent_name": "MiMo-V2-Flash", "weighted_score": 7.95, "brief_justification": "Correctly identifies all three race conditions (totalRevenue, orderCount, errors slice) and provides a proper mutex-based fix. The explanation is clear and covers atomicity, memory visibility, and even mentions atomic alternatives. However, there's a factual error in the example output showing $849.46 when the correct sum should be $799.46 (99.99+149.50+299.99+49.99+199.99)." }, { "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 identification of race conditions, clear fixes with multiple approaches, and practical guidance including race detector usage." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "claude_opus_46", "respondent_name": "Claude Opus 4.6", "weighted_score": 9.6, "brief_justification": "Accurate identification of all concurrency issues, correct fix with mutex, clear explanation of design choices, and actionable verification step." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "gemini_31_pro", "respondent_name": "Gemini 3.1 Pro", "weighted_score": 7.6, "brief_justification": "Correctly identifies data race and proposes mutex fix, but incomplete code snippet and misses slice append race." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "claude_sonnet_46", "respondent_name": "Claude Sonnet 4.6", "weighted_score": 9.35, "brief_justification": "Accurate identification of race conditions, comprehensive fix with mutex, clear explanation, and practical code improvements." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "grok_420", "respondent_name": "Grok 4.20", "weighted_score": 8.8, "brief_justification": "Accurately identifies all race conditions and provides two working solutions. The atomic version is slightly flawed (doesn't handle final read atomically), but the core fixes are correct." }, { "judge_key": "mimo_v2_flash", "judge_name": "MiMo-V2-Flash", "respondent_key": "deepseek_v4", "respondent_name": "DeepSeek V4", "weighted_score": 8.6, "brief_justification": "Accurate identification of race conditions and clear fixes with mutex; alternative atomic approach adds depth." } ], "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)" } }