www.astralcodexten.com/p/moltbook-after-the-first-weekend
1 correction found
Remember, Claude 4.5 Opus has a four hour 50% time horizon.
METR’s published measurements put Claude Opus 4.5’s 50% time horizon at about 4 hours 49 minutes (and later estimates around 5+ hours), not 4 hours.
Full reasoning
Scott Alexander claims: “Claude 4.5 Opus has a four hour 50% time horizon.”
METR—the organization that introduced and publishes widely-cited “time horizon” estimates—has publicly reported a higher 50%-time-horizon for Claude Opus 4.5:
- In a METR post summarizing their estimate, METR states Claude Opus 4.5 has “a 50%-time horizon of around 4 hrs 49 mins.” This directly contradicts the post’s “four hour” figure.
- METR’s later “Time Horizon 1.1” writeup also reports the model’s 50% time horizon as 289 mins under TH1 (which equals 4 hours 49 minutes), and 320 under TH1.1 (which is 5 hours 20 minutes if interpreted as minutes, as shown in the same table formatting). Either way, METR’s published point estimates are not 4 hours.
Because METR’s published estimate explicitly says “4 hrs 49 mins” (and provides the underlying minute value), the statement “four hour” is not accurate as a factual numeric claim.
2 sources
- Anthropic's Claude Opus 4.5 Time Horizon Estimated at 4 Hours 49 Minutes | METR posted on the topic | LinkedIn
“We estimate that, on our tasks, Anthropic's Claude Opus 4.5 has a 50%-time horizon of around 4 hrs 49 mins…”
- Time Horizon 1.1 - METR
Table shows: “Claude Opus 4.5 289 …” (TH1) and “320 …” (TH1.1); elsewhere on the page it states “Vivaria … Claude Opus 4.5 289 mins … Inspect … 270 mins …”