- you have some quite long loop - where every item in this loop is one game event (eg. shot on goal, hit, etc.)
- all of this events are evaluated separately - meaning... first shot (some calculation depending on players' atts etc) and result is no goal... second action is blocked by defenders, etc... then part of these actions are some hits or so - and if player has low tech, the action ends as a penalty...
- this is calculated for both of the teams in a game
- result is just the sum of successful shots...
very oversimplyfied, and only my guess, how an engine could work

