Ratings run the game. That's how I set my line-ups. However, IMO, only a fool continues to do the same thing if it's not working. Logic says the 80/80/80/80/80 player will hit eventually. But keeping him in the 3 hole while he's at .220/.242/.313 after 150 AB is borderline stupid. I make changes in my batting order every 20 games or so. I have a tough time putting that 80s guy on the bench but I do cut his playing time(assuming he's not capable of 162 games) by playing his sub periodically. For me, the roughest thing is pulling the sub if he's .330/.360/.425 even though his ratings say he's a .240 hitter.
It's just chance. There are no streaks, multipliers or "bad" seasons programmed into the game. If you roll dice and hit double sixes 9 times in a row, it doesn't mean the sixes have any better, or worse, chance of coming up the next time. All other things being equal, the 90 power guy will hit more homers than the 80 power guy over the course of time
Hardball Dynasty – Fantasy Baseball Sim Games - Player Profile: Greg Wood
is a good example of a guy I don't bench despite his uneven results. But he has hit everywhere from 2-8 in my line-up..