Research LessWrong Dec 26
Measuring no CoT math time horizon (single forward pass)
By ryan_greenblatt
72 score
AI Analysis
Ryan Greenblatt measures AI models' ability to solve math problems without chain-of-thought reasoning as a proxy for opaque reasoning capability—a key risk factor for scheming. Finds Opus 4.5 has a 3.5-minute no-CoT time horizon and that this capability has been doubling approximately every 9 months.
A key risk factor for scheming (and misalignment more generally) is opaque reasoning ability. One proxy for this is how good AIs are at solving math problems immediately without any chain-of-thought (CoT) (as in, in a single forward pass). I've measured this on a dataset of easy math problems and used this to estimate 50% reliability no-CoT time horizon using the same methodology introduced in Measuring AI Ability to Complete Long Tasks (the METR time horizon paper). Important caveat: To get hum
AI SafetyAI CapabilitiesAlignmentScheming RiskEvaluation