The game of double chess is played like regular chess, except each player makes two moves in their turn (white plays twice, then black plays twice, and so on). Show that white can always win or draw.
Credit: Olympiad Combinatorics - Pranav Sriram
EDIT: I tried a few thing's like finding the specific strategy, but nothing seems to work. I dont know how to approach this question.
This is specific to chess. Hint: At the start, there is a chess piece that you can move twice in the beginning to return to the starting board position. Effectively passing your turn.
We show white (the first player) has a non-losing strategy. Suppose not, then there is a winning strategy for black (the second player). But as white, at the very beginning you can move a certain chess piece twice, and still have the same starting chess configuration. Thus white effectively becomes the second player and having a winning strategy, a contradiction.
(I'll let you figure out which chess piece this is.)