What does the basketball statistic GB refer to?
GB stands for games behind, as in games behind the first place team.
The gb in the question should be GB and stands for gigabytes, which is a unit of measurement in computers. The scale starts at a bit. A bit can be either a 1 or a 0. Eight bits equals one byte, and 1024 bytes is one kilobyte. 1024 kilobytes equals one megabyte, and 1024 megabytes equals one gigabyte. 1024 gigabytes is equal to 1 terabyte.