There's a run length for identical pixels but no run length for literal pixels. Some images barely compress which means there should be many runs of uncompress

There's a run length for identical pixels but no run length for literal pixels. Some images barely compress which means there should be many runs of uncompressed pixels. Even if only a few pixels long, not having a byte of overhead for each should improve size on these pictures. Maybe they just wanted it to win on throughput by having fewer branches.