I'm playing in a roto league for the first time. All of the other leagues that I have played in have been H2H.
So, in H2H with daily roster changes, I would take my reserves and plug them into my starting lineup whenever my primary player had a day off. So if Tulo and the Rockies are off, I put Uribe in at SS. If Ethier sits against a lefty pitcher, I put Andres Torres in. Etc. With pitching, unless the pitcher is an ace, I will look at the matchup a little more closely before I start him.
Is the strategy the same for a roto league? Will you always play a substitute position player? How about pitchers?