http://iscoresports.com/

is there a way to adjust when a courtesy runner comes on after the play has occurred and not marked originally without undoing the batters to that point? for instance: player a hits the ball and player b is the courtesy runner but scorekeeper does not mark the courtesy runner in.

I don't think this is a correction you can make through edits so the only way would be to undo, or override the stats if necessary. You could add a note.

You can sub the runner in by doing an offensive substitution in play by play editing after the batter gets the hit. Then after the runner scores or the inning ends, sub the original batter back in. This will get the stats right.

Great tip!
Had not thought of that..