Why can't you lose a chess game in which you can make $2$ legal moves at once?

Question

So here is the Problem :-

Consider a normal chess game in an $8*8$ chessboard such that every player makes $2$ legal moves at once alternatively . Now imagine that you was asked to play with Magnus Carlsen .Then Prove that it's impossible for Magnus Carlsen to make you lose, or atleast can make you draw.

I was actually stumped when I first saw this . Also I tried thinking many normal chessgames and tried to understand what type of answer this question can take . From here I can say that a check on the $1st$ move made by any player is actually a checkmate . Other than that I have no idea, can anyone help ?

Edit :- I forgot to add another thing . It's given that I will be white and Magnus Carlsen will be black .

Answer 1

While some of the details of the rules may still be ambiguous in boundary situations, it is clear that white can avoid a loss by opening with

1. ♘b1-c3,♘c3-b1

or

1. ♘g1-f3,♘f3-g1

More precisely, if either of these no-ops in fact leads to a position where black can force a win, then white could force a win by playing by black's strategy mirrored.

Answer 2

Taking the idea of @Hagen Von Eitzen in my answer :-

First assume that Magnus Carlsen (Black Side) has a winning strategy . Then if I play either :-

$$Nc3-Nb1$$ or $$Nf3-Ng1$$ as my $2$ legal moves , I can actually get the same winning strategy from Magnus Carlsen , hence that forces me not to lose . This is like a strategy stealing from my opponent .

Answer 3

With the new condition that I will start as white pieces and my opponent (Magnus Carlsen in this case) as black pieces, Scholar's Mate can guarantee a win in 4 moves.

The Scholar's Mate is a 4 move mate meaning black has to play pawn e6 or pawn d5, which is a move only delaying the inevitable mate.

Answer 4

There is a mathematical proof for this

Assume that there is no such strategy by which player 1 (white) would not lose. This would imply that black has a non losing strategy.

now let white move it's knight first, and take the knight back; essentially making black white (or the person who moves first ) now that would mean that black will also have no non-losing strategy

but this contradicts our assumption that black has a non losing strategy. So by contradiction we can prove that white has a non-losing strategy and can never lose.