Simply creating an LLM judge prompt isn't enough. Before deploying it, you must test its alignment with human judgment. Run the judge on your manually labeled data and analyze the results in a confusion matrix. This helps you see where it disagrees with you (false positives/negatives) so you can refine the prompt and build trust.

Once an evaluation becomes an industry standard, AI labs focus research on improving scores for that specific task. This can lead to models excelling at narrow capabilities, like competition math, without a corresponding increase in general intelligence or real-world usefulness, a classic example of Goodhart's Law.

The proliferation of AI leaderboards incentivizes companies to optimize models for specific benchmarks. This creates a risk of "acing the SATs" where models excel on tests but don't necessarily make progress on solving real-world problems. This focus on gaming metrics could diverge from creating genuine user value.

Public leaderboards like LM Arena are becoming unreliable proxies for model performance. Teams implicitly or explicitly "benchmark" by optimizing for specific test sets. The superior strategy is to focus on internal, proprietary evaluation metrics and use public benchmarks only as a final, confirmatory check, not as a primary development target.

There's a significant gap between AI performance on structured benchmarks and its real-world utility. A randomized controlled trial (RCT) found that open-source software developers were actually slowed down by 20% when using AI assistants, despite being miscalibrated to believe the tools were helping. This highlights the limitations of current evaluation methods.

Just as standardized tests fail to capture a student's full potential, AI benchmarks often don't reflect real-world performance. The true value comes from the 'last mile' ingenuity of productization and workflow integration, not just raw model scores, which can be misleading.

Arena differentiates from competitors like Artificial Analysis by evaluating models on organic, user-generated prompts. This provides a level of real-world relevance and data diversity that platforms using pre-generated test cases or rerunning public benchmarks cannot replicate.

Don't trust academic benchmarks. Labs often "hill climb" or game them for marketing purposes, which doesn't translate to real-world capability. Furthermore, many of these benchmarks contain incorrect answers and messy data, making them an unreliable measure of true AI advancement.

Do not blindly trust an LLM's evaluation scores. The biggest mistake is showing stakeholders metrics that don't match their perception of product quality. To build trust, first hand-label a sample of data with binary outcomes (good/bad), then compare the LLM judge's scores against these human labels to ensure agreement before deploying the eval.