Bob Saget replaced John Posey as Danny Tanner in the hit sitcom 'Full House' due to his superior performance in the role. Posey signed a contract and shot a pilot that ABC invested money into, but was suddenly recast and replaced by Saget after the network re-shot the entire pilot scene-for-scene with Saget wearing the same outfit as Posey. The reason for the recasting is unclear, but it's believed that Saget's more natural and underplayed style better suited the character of Danny Tanner, making him the right choice for the role. The way Posey was let go was seen as brutal and unfair, highlighting the cut-throat nature of the entertainment industry.