Trouble with Q vs R endgames


When it comes to separating the Rook from the King, the winning technique is to force a zugzwang... a position where the opponent is forced to move and thereby to ruin his defensive arrangement.
Consider this position with Black to move:
Black gets mated or loses his Rook in all variations.
But what if it's White to move? Then you win by zugzwang:
,,, reducing the position to an already-solved problem.