Ok, even though sprite movement has no real restrictions BGGET works off of the 16x16 bg tiles. That's why BGGET(L,X,Y) looks more like BGGET(L,PX/16,PY/16). This is where order is important, if you add 1 to PX before dividing by 16 (by parentheses) you're change the "hitbox". If you add 1 after you're changing the tile