Metallica's 1986 album "Master of Puppets" is regarded by guitarist Kirk Hammett as the band's creative peak and masterpiece. Released following their initial success, the album represented a significant breakthrough that showcased their pioneering mastery of thrash metal and has become one of the most influential records in rock history. With approximately 20 million copies sold, the album's reach and legacy remain unmatched within their discography.

In a 2012 Rolling Stone interview, Hammett reflected on the album's creation, noting that the band had been performing together for roughly three years at that point and were "definitely peaking." The record balanced energetic headbangers like its title track with more contemplative pieces, and Hammett credited the extensive studio time spent experimenting with guitar sounds and overdubs as essential to achieving its rich sonic palette. The album's release coincided with the band's most significant touring opportunity to date, opening for Ozzy Osbourne, which proved instrumental in establishing their prominence in the heavy metal scene.