Would someone be able to tell me how to set this up?
Thanks

This is from the FAQ pinned at the top of the SLB forum:

What Does Starter 2A/2B or Tandem 2A/2B Mean? Probably the most asked question in the SLB forums

Skunk you rock. Thanks for the info!

Tandem is typically used when you have a starting pitcher with low ip/g. He'll be removed early then you have somebody to eat up a few innings so your bullpen doesn't get used up. Also useful if you have one of those high inning relief pitchers and there's no way he'll get all of his innings from the bullpen use him at Tandem B to get his innings. I sometimes use it when one of my Long Relievers isn't getting used I'll give him some Tandem B innings to keep others rested. Some people use Tandems to alternate Left and Righty pitchers to challenge those who use different lineups against lefties. Is there a downside to using tandems? It doesn't mesh well with the use of pinch hitters. Can be more cumbersome to manage. And arguably you may possibly get a few less innings out of your pitching staff.

I find tandem works well when you have to deal with imbalanced rotation innings for whatever reason... if you, say, have 2 pitchers at 225, a pitcher at 150, and a pitcher had 350, you can set the 350 and 150 in a tandem, limit 150 to a 40 pitch count, and try to maximize innings that way...

I like to put 2 guys with 150-200 innings in front of pitchers like pedro and maddux. Then you end up with ridiculous win/loss records.