So, I was just adopting my guy @ShadowCellen(not my alt, and sry). And in one of the game he just freak out and just give up lol, so I ended up checkmating him with long castle, and got this achievement.
The legit first ever time I have done this achievement. There is another achievement which is to checkmate with a king move(discover check with king and mate).
I believe over 80% of chess.com don't have this achievement xD
So, I was just adopting my guy @ShadowCellen(not my alt, and sry). And in one of the game he just freak out and just give up lol, so I ended up checkmating him with long castle, and got this achievement.
The legit first ever time I have done this achievement. There is another achievement which is to checkmate with a king move(discover check with king and mate).
I believe over 80% of chess.com don't have this achievement xD