On the standings page what does GB mean?
GB means games behind the conference leader. The scale of GB goes by 0.5, so when a team loses or wins, their GB changes by 0.5 unless it is the conference leader. If one team loses and the other wins, there is a 1 game difference that will occur.
In AFL, 4 points are given for a win, 2 points are added to the ladder for a draw and nothing for a loss.
On the other hand, if a game score lists "GB" on the scoreboard, the 'G' signifies the number of Goals that team has kicked for the match and the 'B' states the number of "behinds" it has kicked [That does not mean 'backsides'LOL]. A behind is scored when a player does NOT cleanly kick the ball between the middle pair of "goalposts".
Four posts are placed in a straight line, facing the field of play, which act as the overall scoring target at each end of the field. However, only a ball, kicked so that it passes between the two bigger middle pair of posts, untouched by any other object including by the goalpost itself will score a goal - worth 6 points in the game. A ball crossing between any of the posts in any other manner, is called "a behind" and contributes only one point to the overall team score.
So, if the scoreboard, under the "G" states 7, that means the named team has scored 7 goals = 42 pts. The next column on the board states the number of "B": so a '3' under B means the team has scored 3 behinds or pts, as each behind equals a point.
So the scoreboard might read, for instance:
................. G B Pts
Geelong ... 7 3 45
St. Kilda ... 8 5 53