The central part of the game engine is how the half court offense/defense works. The general idea is that a team gets a series of opportunities to score. What kind, and what the quality of those opportunities are is a function of the offense they are running, the matchups between the offensive players and their defenders. A player must decide whether the opportunity presented is good enough to take a shot… this of course changes as a function of amongst other things… the shot clock, the players experience, the score of the game, the history of the quality of shots the team has seen recently, the offense the team is running, and whether that rookie shooting guard of yours thinks he knows better than the coach does how good he is at making jump shots.