Mikhail Tal, the roguish, doomed Latvian who changed the way chess players think about attack and sacrifice; Tigran Petrosian, the brilliant, henpecked Armenian whose wife drove him to become the world’s best player; Boris Spassky, the prodigy who survived near-starvation and later bouts of melancholia to succeed Petrosian-but is best remembered for losing to Bobby Fischer; and “Evil” Viktor Korchnoi, whose mixture of genius and jealousy helped him eventually surpass his three rivals (but fate denied him the title they achieved: world champion).