White's losing mistake may well be 4 Qg4!
@Dario19503 Excellent game. Fun to play it through. Congrats !
@achja Thank you, Albert! Long time no see!
#11 That move recommended by Nimzowitsch is outdated and not a very promising choice against a versed player. Principled 3. c3 was better and natural, and is considered the main line nowadays.