I am interested in the 4 knights scotch, I want to use against the petroff. I wonder how do I play against counterattacks in the centre, like 1.e4 e5 2.Nf3 Nf6 3.Nc3 Nc6 4.d4 d5?
BTW - Ruy Lopez is worth studying, I mess up the move order and got severely punished for it in many of my games!
Play Belgrade gambit, a variation of the four knights (look it up). It looks crazy but it has worked very well for me, and it is very difficult to defend against. Even the worst variations lead to an equal position
this is especially good at elo 1500-1600 level (I am 1777). Give it a try - 1. e4 e5 2. nf3 nc6 3. Nc3 nf6 4.d4 ...exd4 5. Nd5
Has z99j been here since 2013?
Anyway, possibly helpful:
The Four Knights: Move by Move by Cyrus Lakdawala (2012)
https://web.archive.org/web/20140627040728/http://www.chesscafe.com/text/ebcafe06.pdf
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
The Ruy Lopez: Move by Move by Neil McDonald (2011)
https://web.archive.org/web/20140627022042/http://www.chesscafe.com/text/hansen153.pdf
Playing 1.e4 - Caro-Kann, 1...e5 and Minor Lines by John Shaw
http://www.qualitychess.co.uk/ebooks/Playing1e4CaroKannandothers-excerpt.pdf
A number of recent books have advocated the Italian game for White:
My First Chess Opening Repertoire for White by Vincent Moret
https://www.newinchess.com/Shop/Images/Pdfs/9033.pdf
https://www.chess.com/article/view/how-to-understand-openings
A SIMPLE CHESS OPENING REPERTOIRE FOR WHITE by Sam Collins
http://www.gambitbooks.com/pdfs/A_Simple_Chess_Opening_Repertoire_for_White.pdf
Winning with the Slow (but Venomous!) Italian by Karsten Müller and Georgios Souleidis
https://www.newinchess.com/Shop/Images/Pdfs/9037.pdf
Alright with the Tortoise joke no one is laughing!