The estimate starts at minute 10. Before that the model measures worse than guessing the base rate, and a number there would be noise wearing the face of analysis. 10:00

Our own model, fitted by logistic regression on 390 maps from this site’s history, using net worth, experience and buildings still standing. It is NOT the Dota Plus number — Valve does not publish that probability in any public API, so nobody outside the game client can show it.