The “1 best” version likely originated from a meticulous encoder who:
In standard theatrical releases, 300 is presented in a widescreen aspect ratio (2.35:1), which uses black bars at the top and bottom of the screen to focus the viewer's attention. An version, however, "opens" these bars to reveal more of the original film frame captured by the camera. 300 2006 open matte 1080p webdl x265 hevc 1 best