How to win at chess when your opponent is keep on copying your moves?

mate him 1 move before he mates you.

1.e4 e5 2.Nf3 Nf6 3.Nxe5 Nxe4 4.Qe2 +-

You can copy as Black in many openings but some no . In fact you can do very very well with Black disregarding a useless move ... THEN you are "White" where "Black" created a useless sometimes Weakness

Longest symmetrical game: 16 moves

https://timkr.home.xs4all.nl/records/records.htm

@SHG2005 said in #15:

@edot12345 Hypothetically speaking, is it absolutely true?

nope, bc the move has to be the same move that the opponent played on the previous move. you can't give a check while blocking a check using the same move that gave the check in the first place

ok my explanation is kinda crap