This is just awful. The Pirates had a chance to blow their game with the Giants wide open in the sixth inning after Jean Machi walked Chris Stewart to load the bases with one out.
Travis Snider, who was on second base at the time of the walk, inexplicably began to trot down to third base. Machi noticed, and alertly threw to shortstop Brandon Crawford, who got Snider in a rundown and tagged him out. Gaby Sanchez then broke from third to home, and Crawford fired the ball to Machi, who got Sanchez in a rundown and threw the ball to Pablo Sandoval for the third out.
This is just mortifying for the Pirates. While they still led after this half inning, and it clearly wasn’t the sole reason they lose the game, it was pretty clearly a major brain fart on the basepaths by Snider.