in some games, dependant upon what your tactics are, your coach will puut the best players on the court, based on stamina/skills etc.
So for instance, in some games, if you play FCP, and man-to-man, and your starters have crappy stamina, your bench players may in fact get lots of minutes compared to say, if you played Low-post and 2-3 zone.
There are many factors like this, ive only highlighted some basic examples, but essentially, what can happen is that, given a set of criteria, such as offense/pace/stamina/enthusiasm/gameshape/tactics, a teams scrubs will be left on the court because the coach has decided that they would have performed better than the starters.
A basic real life example would be like, if you told your starters, to play their ring off for 3 quarters. After 3 quarters they are all flat on their backs, so coach sends in bench. Bench is going to perform better than starters correct?
So yer. its not always such a simple case of 'oh my coach shoulda put my starters back in, becuase my scrubs were getting killed'.... maybe if your coach put your starters in you woulda lost by more.
Just a different way of looking it really :) It does happen and the more you play the game, the more you learn how to lessen the chances of these things happening. Just experience is all. best of luck.