From Blaseball Wiki

Annihilation is a state of being in which a Blaseball player has ceased to exist and in which no material, metaphysical, or material evidence of their existence remains at any point in Blaseball History.

Due to the nature of Annihilation, it is unknown (and inherently unknowable) which players have been subject to Annihilation, though official League estimates claim that between 4-78% of all players may be Annihilated over the course of a regular Blaseball season.