Top Frontier AI Models Top Out At C+ ... Barely Better Than Old Models

InnovationConsumer TechTop Frontier AI Models Top Out At C+ ... Barely Better Than Old ModelsByJohn Koetsier,Senior Contributor.Forbes contributors publish independent expert analyses and insights. Journalist, analyst, author, podcaster.Follow AuthorMay 20, 2026, 03:10pm EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.Top frontier AI models aren't that top. In fact, according to a new study, they max out around the C+ level.gettyTop new frontier AI models from OpenAI and Anthropic are more expensive, and they come with gaudy new claims of higher intelligence and superior results. But according to a new study of 510 questions by expert network Pearl, they don’t actually improve performance all that much. In fact, they're all clustering just below the level where professionals would actually trust them. Pearl tested 25 of the world’s leading AI models including GPT-5.5, Claude Opus 4.7 and Gemini with real licensed professionals judging the answers. The result: none of the models exceed 73%.Which is probably a C grade, maybe a C+.GPT-5.5 was tops at 72.7%, with 5.1 at 72.0%Claude Opus 4.7 scored 71.9%, with 4.6 at 69.8%Gemini 3 Pro hit 67.3%, with 2.5 Pro at 64.5%"Benchmarks measure whether a model can pass a test. We’re asking whether a professional would trust the answer, and right now, the answer is no," said Pearl CEO Andy Kurtzig. "Almost right is still wrong."Pearl assembled roughly 510 questions across five professional domains: business, health, law, pets and technology. None had never been released publicly and were not available to model developers during training. Each of the 25 AI models received identical prompts with no tuning or prompt engineering, and responses were graded by credentialed experts on a 1-to-5 rubric measuring four dimensions: correctness, completeness, prioritization, and professional judgment. That last criterion is where Pearl is ma...