Almost Certain Escape from Black Holes in Final State Projection Models

Recent models of the black-hole final state suggest that quantum information can escape from a black hole by a process akin to teleportation. These models rely on a controversial process called final-state projection. This Letter discusses the self-consistency of the final-state projection hypothesis and investigates escape from black holes for arbitrary final states and for generic interactions between matter and Hawking radiation. Quantum information escapes with fidelity $\approx (8/3\pi {)}^2$: only half a bit of quantum information is lost on average, independent of the number of bits that escape from the hole.