My line in this one is exf5
The Bluestone Counter Gambit

We have heavily analysed it in another thread, If I could get some people from that thread to help in this one, it would be appreciated.
the verdict is that it is playable
All right, I'm here. For those that haven't seen the King's Gambit: Obscure Lines thread, I'm one of the major contributors of the Bluestone, along with jetfighter and melvinbluestone. I have a ton of the variations in the dxe5 lines. For now, because there is no real "gambit" in them, I'm going to call it the Bluestone Counter Gambit Declined, or the BCGD.
Bluestone: 1. e4 e5 2. f4 d5 3. d4 f5
BCGD: Bluestone + 4. dxe5 fxe4
BCGD Main Line: BCGD + 5. Nc3 Bb4 6. Bd2 c6 7. g3 Nh6 8. Bh3
Exchange Variation: BCGD Main + 8...Bxh3 9. Nxh3 Bxc3 10 Bxc3 O-O 11. Qd2 Nd7 12. O-O-O Qb6 (typically followed by 13. Bd4 Qa6)
Blockade Variation: BCGD Main + 8...Nf5 9. Bxf5 Bxf5 10. Qe2 h5
Knight's Stable Variation: Blockade + 11. Na4 Bg4 12. Qe3 a5
Poisoned Knight Variation: Knight's Stable + 13. Ne2 Nd7 14. O-O-O b5 15. Rde1 bxa4 16. a3
Jitterbug Variation: Knight's Stable + 13. Nc5
Poisoned Pawn Variation: Exchange + 14. Qc3
I highly reccomend all of you haters learning the Bluestone. It is very easy to transpose into, and plays a great game for both sides.
Here's an example of a transposition:
Oh, and jetfighter, if it's okay with you, I'm going to dub exf5 the BCGA (Bluestone Counter Gambit Accepted), because of how 5. fxe5 makes it an actual gambit.
It is not a bad position, I am playing a game now in it, and have a central majority, and in a minute will have a lead in development
It does pretty much what the Falkbeer does, like jetfighter said. 1) it declines the gambit 2) it still gives black some "counter-attacking style" 3) after the gambit of 4. exf5 Bxf5 5. fxe5 black is in a very nice position with a minor piece out and a Qh5+ onslaught soon to come (very soon to come).
And your thing about the symmetrical position and how black's kingside is weak, it would be the same if he played 2...f5, and that's considered a very sound move.

I was to lazy doing my own diagram so I simply stole it from Gregory Serper.
If black played 2...g6 it wouldn't be much of a problem though, the puzzle is mainly designed to be instructive, not to show the best possible play for both sides. 3...fxe5?? is the really big mistake, black can still save himself by going 3...Qe7.
6...d5 is a better try but also looses of course.
dude that is just wrong, anyone can do that, it takes real skill to do it yourself, any way, you did demonstrate your point, and I absolutely love greco games.
Black's compensation for the lost pawn is the development of the bishop of the nice f5 square. Black gains tempo after dxe5 because white had to take the time to take the pawn. White has also overextended his pawns.
I posted some new lines in there. Not sure how sound they are but they seem playable.
This Idea was started in the Kings Gambit thread talking about obscure lines.
This move has never been found in a master level game, but we have come to the conclusion that it is even for both players, and is extremely tactical, and has some nice variations. I will not try to post them, only how to get to the position. Also if you can add some variations