@Vass: Doesn't your final position favor Black?  16...Ke7; Black's pawns are better; White's rooks appear to be no more active than Black's.

@Taljechin:  I don't think 4...d5 "might rebound," though it may well not be the best move.  It's active, and it's interesting that it does indeed seem to be challenging to meet.

My tiny contribution to this thread - 7.Bh3!?
I'm very sorry I don't have my PC (with my engines) to help me right now. So I post some "human"  variations.. Anyway, I hope it's worth it..

Severino wrote on 07/19/12 at 07:59:32:

There is an entry on the Fyfe G. in the Oxford Companion to Chess, so Hugh Myers must have known it. [An US paper reviewing the Handbuch wrote: "the work belongs in every household". Right - and everybody needs a OCC.] But when an author tries to make 1...Nc6 playable for Black, there is much to do, ignoring the Fyfe can be forgiven. - More research is necessary, the Glasgow Weekly Herald is an important source, but unavailable online. Some games were in the Glasgow Herald, which is online, but only until 1900.

Quote:


If you're right about that rooks-versus-queen position, yes. 

Black also has 11...Bb4+, which looks interesting.  I looked at 11...Bb4+ 12.Kf2 Ne7 12.Qb3 a5 13.a3 Bd6 and the position is unclear to me.  Probably best is 14.Re1 Bxe4 15.fxe4 O-O with what looks to me like a hard fight for both.

You're mistaken.

1.e4 e5 2.Nc3 Nc6 3.d4 Nxd4 4.f4 d5 5.exd5 Bf5 6.Bd3 e4 7.Nge2 Nf3+ 8.gxf3 exd3 9.Ng3 Qd7 10.Nce4 dxc2 11.Qxc2 Ne7 12.O-O h5 13.Be3 h4 14.Nxf5 Nxf5 15.Bf2 (this was your proposed play for both sides after 9...Qd7) 15...Rh6 16.Rac1 O-O-O 17.Bxa7 b6 18.d6 Bxd6 19.Bxb6 Bxf4 20.Rfd1 Bxc1 21.Rxd7 Rxd7 22.Qxc1 Rxb6 

This is not an ending the way I talk about endings.  It certainly is not analytical.  It will take some pretty deep investigation.  I respect your opinion; nevertheless provisionally, I would somewhat rather be Black.

Black also has 11...Bb4+, by the way.

Smyslov Fan: No, there's absolutely nothing wrong with using a computer to do analysis, and I am sorry if I suggested that there is.  I'm just saying, it's a little funny when you suggest some moves based on intuition and people seem to come after you with Rybka 1000 or whatever the latest version of that is.  But in principle of course, chess truth is what these discussions should be about, and computers are one way of discovering that.

Others: 4...d5 is, of course, played in reaction to 4.f4, and I think that so far it has been seen to be a good move.   It's the sort of move we see all the time in good chess. Whether it is as good as 4...Bb4, for example, remains to be seen.   Of course I exaggerated when I proposed 4...d5 and put "!" after it.  "!?" would have been the precise way of putting it, but I wanted to call attention to my idea.

But even if 4...d5 can only be played with expectation of equality, a conclusion to which Stefan's arguments seem to point, that in itself limits the utility of this gambit, just like the availability of ...d5 limits the utility of the Danish Gambit which, like the Fyfe, is perhaps best refuted by other means.

That 19th Century players always took the pawn is hardly surprising, is it?  This this game is played with a different understanding now than it was then.  In any case I don't claim that keeping the pawn is not also good. 

But that's enough meta-theory for me.  Since I would rather be Black in that two-rooks-versus-queen position we uncovered, for the time being I will regard 4...d5 as =+.

Markovich wrote on 07/18/12 at 03:36:27:

I was aware that you are using only a handheld computer in your vacancy, and guessed that you are not connected to some supercomputer. But I am used to let the PC check some lines overnight. It is helpful to know that 6.Bd3 fails to ...b6. Now we can focus on 6.fxe5. Forget my claim that the complications "are favouring White", because I am not sure, but White is not playing for two results only. If the King's Gambit has a right to exist, this line must have it too. 

4...d5 is the kind of piece-activating move which is perfect to punish irregular play from White, like h2-h3 or c2-c3. However, White's sacrifice d2-d4 is made of the same cloth, it would be surprising if in this battle White can be overrun by simple play. In the old games with the Fyfe, nobody used 4...d5. Instead they followed Lasker's "take the pawn and return it when you see an opportunity to profit positionally".