The "Crucible curse" (also known as the "The curse of the Crucible") refers to the fact that no first-time snooker world champion has retained his title the following year since the event moved to the Crucible Theatre in Sheffield in 1977. The last player to successfully defend his first world title was John Pulman in 1964, when the championship was still decided by challenge matches.
The following first-time champions did not retain their title the following year. Of the fifteen players to have won their first championship at the Crucible Theatre, five lost in their first match as defending champion (Terry Griffiths in 1980, Steve Davis in 1982, Dennis Taylor in 1986 Graeme Dott in 2007, and Neil Robertson in 2011) and only two went on to reach the final: Joe Johnson in 1987 and Ken Doherty in 1998.
In the meantimes, the titles were won by players who had already been world champions (so the "curse" did not apply). Three players have even won consecutive titles: Ray Reardon (1973–76), Steve Davis (1983–84 and 87–89) and Stephen Hendry (1992–96), but only after they experienced the "curse".