I made half a move?

I think the 'half' move comes from when you make a draw- I have only one drawn game, and this is in my profile:
Avg./game when Draw: | 52.5 |

I think the 'half' move comes from when you make a draw- I have only one drawn game, and this is in my profile:
Avg./game
when Draw: 52.5
The sum of the white and black moves should equal the total, no?
On that basis, there should be 2 halves, I think, not one.




Often a "move" in chess is two plies, white takes a turn/black takes a turn. So I don't think the .5 has anything to do with drawing, winning, or losing the game.
Why the total line didn't add the fraction, I have no idea--must just round up.
From my detailed stats...
Wins, Loses, Draws, Moves.
Half a move?