Equation 1 · Ten Failure Modes That Define Production Claude Code Use
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Symbol T_50
the task duration completable at 50% reliability at year t , METR’s fit is.
Symbol t
t is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
subscript
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What the article says around this equation
It is intuitive to expect an agentic session to improve as it accumulates context about a task. The measured pattern runs the other way. METR’s time-horizon research tracks the length of task — measured in how long a skilled human would take — that a frontier model can complete autonomously with a given reliability, and finds current frontier models near 100% success on tasks taking a human under four minutes, collapsing to under 10% success on tasks taking more than about four hours, with Claude 3.7 Sonnet reported specifically among the models exhibiting this drop-off [ 13 ] . The organization’s headline trend — the task length completable at 50% reliability doubling roughly every seven…
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It is intuitive to expect an agentic session to improve as it accumulates context about a task. The measured pattern runs the other way. METR’s time-horizon research tracks the length of task — measured in how long a skilled human would take — that a frontier model can complete autonomously with a given reliability, and finds current frontier models near 100% success on tasks taking a human under four minutes, collapsing to under 10% success on tasks taking more than about four hours, with Claude 3.7 Sonnet reported specifically among the models exhibiting this drop-off [ 13 ] . The organization’s headline trend — the task length completable at 50% reliability doubling roughly every seven months over six years of measurement — is worth writing as an explicit model rather than a slogan, because it is the empirical claim the section rests on: if is the task duration completable at 50% reliability at year t , METR’s fit is
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