SWE-bench Verified is at 97, and the top of the table is hard to read
SWE-bench Verified measures whether a patch written by a model makes a real repository test suite pass[1]. The score comes from running those tests in a container, not from preference judgements or synthetic checks[1].
On the Steel leaderboard, Claude Opus 5 leads at 97.0 percent from an independent Vals.ai run (September 2026), with a second Claude Opus 5 entry at 96.0 (July 2026)[1]. Then come Claude Mythos 5 at 95.5 (June 2026), Claude Fable 5 at 95.0 (June 2026) and Claude Mythos Preview at 93.9 (April 2026)[1].
Conditions differ per submission, and the two Opus 5 rows show how much. The 97.0 came from an independent run on a bash-only harness in isolated Docker containers[1]. The 96.0 is a five-trial average in the standard configuration[1]. The 95.5 on Mythos 5 is an average over five trials with adaptive thinking at maximum effort[1]. Set beside a number from a single trial, none of these are measuring the same thing.
The leaderboard attaches its own warning. It calls the benchmark mature and heavily exposed in public training data, and says top frontier scores should be read with contamination and test-design caveats, especially when comparing very high-scoring systems[1]. It calls the benchmark strong for public issue-resolution work and weaker as a frontier signal once scores approach saturation[1].
The official SWE-bench site lists five variants: the original, Verified, Multilingual, Multimodal and Lite[2]. A score is comparable only against another score on the same variant.