In my (limited) experience the star pitchers usually dominate. The exception is often when a team has very poor defense so that ground balls and fly balls that are normaally outs become base hits - or perhaps that inning ending double play only got one out.

There are times when the game seems stuck in a rut and a team gets hit after hit or wild pitch after wild pitch. I attribute that to a problem in the random number generator used by the game program, not to the lack of value given to good pitching.