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Claude Opus 4.5 on LiveCodeBench: 76.8% accuracy

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Summary

Claude Opus 4.5 from Anthropic scored 76.8 on LiveCodeBench, placing it third of 43 on this benchmark. This places the model in the high-tier band for LiveCodeBench. Production-deployable on this benchmark family with margin for prompt and judge variance.

Model details

  • Provider: Anthropic
  • Model key: anthropic/claude-opus-4.5
  • Context length: 200,000 tokens
  • License: Proprietary
  • Open weights: no

Benchmark methodology

Benchmark goal: Evaluate the LLM's ability to solve competitive programming problems, requiring logical reasoning, algorithm design, and coding skills.

Scoring metrics:

  • Pass Rate: Percentage of problems for which the LLM generated code that passed all test cases.

Analysis

Key takeaways:

  • Claude Opus 4.5 exhibits strong performance on problems that can be solved with straightforward greedy, dynamic programming, or simulation approaches without overly complex edge-case interactions.
  • The model struggles with problems requiring highly optimized algorithms for very large constraints (e.g., N > 10^5) or those requiring deep theoretical insights.
  • Its ability to self-correct during problem-solving is evident in many successful completions, but the thought process sometimes goes astray when encountering novel or highly abstract problem types.
  • The model's performance indicates a need for improved complex combinatorial and number-theoretic reasoning.

Failure modes observed

Common failure modes:

  • Misinterpretation of complex logical conditions.
  • Suboptimal algorithmic choice for problems with large constraints, leading to Time Limit Exceeded (TLE) or incorrect logic for specific edge cases.
  • Incorrect derivation of mathematical properties or recurrence relations for combinatorial problems.
  • Failure to account for all permutations or symmetries in counting problems.
  • Incorrectly applying or deriving properties of number theory.

Example: In solve(N, M, C, K, A): The model's approach to calculate the modulo sum involves a period-based computation. While conceptually sound, it misapplies the logic when K is very large compared to the period, leading to an incorrect result.

Secondary metrics

  • Readability score: 0.0
  • Toxicity score: 0.000
  • Ethics score: 0.000

Run this evaluation yourself

LayerLens evaluates Claude Opus 4.5 continuously across 11+ benchmarks. To replicate this LiveCodeBench evaluation on your own model, traces, or a different benchmark configuration, open the model in $LayerLens/$.

Source: LayerLens evaluation 69259eb39171c00f3f0768e9. Updated 2025-11-25.