Changing tactics can change the course of the game completely, I did it couple of times this season. But what should be changed to what, and how to start the game correctly -- these are the questions.
If tactics and orders don't work, I make radical changes and hope for the best. It often works.
And if something does work, I try not to breath =] Many times I was leading with good statistics, and changing orders to protect the lead (to defensive, short, off) ends with the opposite result.