loinghorns 25 years since their first storic encounter. today in spain, th resumed their rivalry with the first of 12uick fire games. when they first met, though, it was more at it. the year was 1984, and for nearly half of, karpov's impregnable play against kasparov's material brillianc the match w called off after five months ter fears the players were exhausted. by the time ty met ain the followinyear, kaspov was rey to take the crown,a title he held until 2000 he then swappethe thrust of the chess boarfor th of russian politics, briefly beg arrested and thenimprisoned for potical dissent. >> this regi is criminal. >> in jail, hisld opponent visited m. heir rvalry is intense, but the respect mutual. today' conte, a reminder why for so many of the 1million people w will be watching, they remain theest players ever to have lifted upon -- lifted apawn. >> this is "bbc wod news." headline for yo this hour -- world leaders attending a united nations climate summitn new york have been warnetime is running out to tackle global warming. palesti