I play petrov's, so I feel I should know it.
Yes, you should know the defense to Cochrane and Ursov gambit.
5 Bc4+ d5 6 exd5 Bd6
5 d4 g6
6 Nc3 d5 / 6 Bd3 Bg7
The engine will help you the rest of the way....but you should play it out to see what the plan is.
It is long known now that the best answer to 5.d4 is 5...c5!
Yes, that is what I have played. I also played a low rated blitz game where after I took on c5, he took back with the d pawn, giving me his queen.
Since 5.d4 c5! 6.dxc5 d5! 7.e5 Ng4 has been proven to be very good for Black, the only really viable option for white is 5.Nc3 (played in the aforementioned Topalov- Kramink game).
It is long known now that the best answer to 5.d4 is 5...c5!
You can hash out your long outdated human book with the long known engine logic of any engine....but if you did that you wouldnt be promoting c5 or would you? BTW, Id be curious what engine plays 6 dxc5 and not 6 Bc4+. You are a good player, but your strength is certainly not openings.
It is long known now that the best answer to 5.d4 is 5...c5!
You can hash out your long outdated human book with the long known engine logic of any engine....but if you did that you wouldnt be promoting c5 or would you? BTW, Id be curious what engine plays 6 dxc5 and not 6 Bc4+. You are a good player, but your strength is certainly not openings.
5...c5 is known to be the best move since the late seventies, when Aldis Vitolins and several other Soviet masters were analysing the Cochrane. Needless to say, engines did not exist back then.
I was at that time a young candidate master (I never got the title of the National Master), and I was getting information from the legendary magazine "Shakmatny Bulletin" (published only in Russian, and dirt cheap).
on highest levels i remember (only) one game, Topalov-Kramnik, Linares, 1999.
generally speaking, at lower level think it is playable, even not fully correct.