Jammin' Jamin 2112
It's quite an anomaly considering that Lars never used double-bass for a groove in any other Metallica song (He of course used it for little bursts, like in One). Then there's the fact that, as far as I can tell, Metallica never played Dyers Eve as part of a live set back in their day. Youtube has bootleg and pro shot videos of almost every concert imaginable, and I can only find one example of Metallica playing Dyer's Eve in the 80's or 90's, as part of an audience-requested encore. In that video Lars skips the double-bass part like he does in their more recent concerts. I've seen zero evidence that Lars was ever able to play the studio version of that song.
- Lars actually did play it in studio. He practiced double-bass until his stamina was good enough to play that one track. Then he got lazy and let his calves get out of shape. This makes him an unrespectable drummer, in my opinion. Dave Lombardo still plays his double-bass as fast as on their old tracks, and he's like 50 years old.
- Complete fraud. The track overdubbed a sped-up recording of Lars doing the double-bass groove.
- Performance-enhancing drugs for that track. We know that Lars used to do a lot of cocaine.