A trap type opening against Owen's Defense

The following game is Gioachino Greco vs. Unknown:

I understand very few people will play 3...f5, but if they do, this is how to counter. 

this is old news friend.

this line can catch an umprepared player. black needs to play c6 here.

this is practically methinks the most difficult line for black to play agaisnt.

Of course it's old news. The game was played by Greco. I figured there were some other people who didn't know about it, like me lol

its the first "game" covered in the chessmaster's series famous games. The "Game" was almost certainly a composition and not a legitimate game.

Yep, Chessmaster is where I got it

@pfren f5 is good. Nothing wrong with creativity.

F5 is considered "book" technically, only this is the right continuation:

I used to play ...f5 but stopped after my kingside kept getting exploited. Simon Williams believes in the move but it isn't as solid

3..f5 loses by force. Lol.

the line that allows kxg8 may very well still be winning but it is by far the least convincing of the winning continuations. In fact, the lichess database even shows one master level game where a 2300 lost to a 2200 in this very position. @pfren  As usual, is correct, the qf5 approach and the nh3 approac is the way to go. I put some analysis on continuations with qf5 above.

there is actually a cousin line in the english defense, that was objectively superior and for some time unclear as opposed to busted like the f5 owen line.

It is now known that this f5 stuff even in this superior order is busted but it took quite while to figure out decidedly. Miles even eeked out a draw vs Walter Browne in this line.

fortunately for english defense fans, 4...nc6 seems to hold fine, (i dont think 4....bb4+ is fully reliable here), or playing it via the 1.d4 b6 or 1.c4 b6 move order playing bb7 in move 2, not allowing this specific formation unless white commits to something like nc3 allowing bb4, or f3 or qc2 both allowing qh4 or nd2 being clumsy.

I see. 

Nice