Game Points

A group of children divided themselves into 2 groups, $A$ & $B$ and play a game. The game is played on a court of length $L$ with a target to goal **more** than the other team. If the goal is done from a distance less than $z$ from either side of the court, the team gets $m$ points, otherwise they get $n$ points with $m<n$. No player can goal from a distance greater than or equal to half the court