Defensive Formation

Oracle Text

Rather than the attacking player, you assign the combat damage of each creature attacking you. You can divide that creature's combat damage as you choose among any of the creatures blocking it.

Card Rulings

10/4/2004 Damage assignment choices from Trample and other things which allow alternative damage assignments for attacking creatures are all made by you.
3/1/2010 With the exception of ignoring the damage assignment order, you follow all the normal rules for damage assignment.