I didn't come up with this idea but it was a really good one that was on IMDb's messageboards (when they had those, remember that?) so I thought I'd add this idea to this board instead, anyway from how I remember it.

This movie has Fresh and his father (played by Sean Nelson and Sam Jackson) playing alot of chess together (in fact I don't believe they have a scene together where they don't).

Anyway, Fresh uses his chess-skills to maneuver his enemies and get them to do exactly what he want them to (which even I understood lol) anyway to the bit I never understood until reading the messageboards of IMDb was this:

Chuckie, the tough guy puertorican kid and best friend of Fresh was a chess-piece as well. He was Fresh's knight and Fresh knew all along that having him deal drugs with him wouldn't work out very well, he knew that he would be bragging about it and making enemies and that could potentially be troublesome for him but in the end the goal of chess is to take out the opponents king and you are gonna lose some pieces on the way of doing so.

He probably didn't mean him to get killed but it was a risk he was willing to take, he put his knight (Chuckie) in danger so that he could save the queen (his sister) and in the end take out the king (the abusive 'boyfriend' of his sister).